Painting and Installing a Trunk Mounted Spoiler

I love the looks of my Saab 9-5, its what drew me to the car.  As soon as I saw pictures of it I knew I wanted it.  Despite how good looking I think the car is I always thought the rear was a little bit plain.  This year while vacationing in Maine, home to more Saabs than I’ve seen anywhere else, I saw a 9-5 that had the factory trunk mounted spoiler on it and I thought it complimented the car very well.

I wanted to see if I get my hands on that same spoiler to add to my car, luckily carries this exact spoiler!  I placed the order then set about gathering my supplies.  They have a ton of other paintable spoilers to, which this DIY will also apply to.  Check them out here:



The trunk mounted spoiler comes in primer and ready to paint, so yes you will have to get some color matched paint for your car.  Do not ever under any circumstance bolt an unpainted accessory to your car.  Seriously, don’t.  Do you want to look like a high school kid that just watched Fast and the Furious for the first time?  No?  Ok, good, paint your accessories.

You’ll have to find a shop near you that specializes in mixing automotive paint or find a source online.  Luckily I have a place near by that does just that.  Try to find a local source for your paint, it will save you money and time over ordering online, only order online if you have to.

You can get an acrylic paint that does not require a clear coat, or you can go with the base coat/clear coat option, I chose the latter to match the car better.

You’ll also need reducer for the paint and hardener for the clear coat.  Talk to the guys at your supplier, they’ll know exactly what you need.

I like to have a few mason jars handy for mixing the various components, they are made of glass and already have measuring lines on them.

Air Compressor and Paint Spray Gun

You really should use an air compressor and proper paint spray gun to do this.  Your paint supplier can usually give you your paint in a rattle can, but only use that if you do not own or can’t borrow a proper compressor.

You also need to make sure that the paint spray gun is correct for the compressor that you have.  Most high end paint guns are meant for High Volume Low Pressure (HVLP), which requires you have a large capacity compressor of around 20 gallons or more.  I only have an 8 gallon compressor so I had to buy a Low Volume Low Pressure (LVLP) paint gun.  Read the manual that came with your paint gun, most of them only require 40-50 psi so set the pressure on your compressor accordingly

Drill and Drill Bits

There is a really scary part to this whole process which we will cover later.  But in order to mount the spoiler you are going to need to drill holes in your trunk, and to do this you will need a GOOD drill and drill bits.  The metal on the trunk lid isn’t super thick but you do not want to try this with a weak cheap drill.  I used this one from the local home store, its not prohibitively expensive and it works very well for drilling metal.

Sand Paper and Steel Wool

For this project I grabbed some 1200 grit wet/dry sandpaper and #0000 steel wool.  You use this to prepare the surface before painting and in between coats.  A roll of good quality blue painters tape will help with lining up the drilling template later.

Time To Paint!

I used two saw horses to prop up the spoiler.  I also used rubber gloves when handling the spoiler to avoid getting any sweat and other hand gunk on it.  The spoiler already comes in primer and ready to paint, still I went over it very lightly with the steel wool before applying the first coat of paint.  Just rub it down smoothly and evenly and when you are done clean off the dust with a tack cloth or I used windex and shop towels.

If you bought your paint reduced and ready to spray, you are ready to go.  If you did not you will have to mix the paint with equal parts reducer before you spray, here is where the mason jar comes in handy.  Fill to one line with paint, then up to the next line with reducer and mix slowly with a wooden or metal stirrer of some kind.

Load up your paint gun and set the pressure properly on the compressor.  I always start out spraying onto a scrap piece of plywood just to make sure that the paint is coming out of the gun correctly, sometimes the first spray is a little rough so its good to get it going some first.

Apply the paint evenly in a steady back and forth motion going off the edge of the piece you are painting.  I usually go back and forth twice for a count of 4 then walk around to the other side and do it again.  Don’t lay it on too thick, just enough to get good even coverage.

Now that you have a coat of paint on and it looks good, Stop!  Don’t touch it! Don’t screw with it!  Say this to yourself out loud of you have to.  You have to let it dry, depending on how hot is is and your paint mixture this usually takes 15-20 minutes.  So relax for a bit.

Once the coat is dry go over it lightly again with the steel wool making sure its nice and smooth.  If there are any rougher spots you can wet sand it with the 1200 grit paper.

For the spoiler, since I couldn’t think of a safe way to hang it, in order to paint both sides I would coat one side, let it dry, sand it, then flip it over to paint the under side of it.  Be very very careful when you do this, if the paint on the top isn’t dry you will screw up the piece and then you’ll have to sand down and start all over.  Trust me, this is what happened to me the first time through.

I repeated this whole process until I had 3 solid coats on each side and I was happy with the result.  Another round of steel wool and we can move on to the next step.

Applying Clear Coat

If you opted to get the bast coat/clear coat type of paint you have to apply a clear coat after the base, obviously.  The clear coat gets mixed with equal parts hardener, again the mason jars come in handy.  If its a particularly hot day you can use a little bit less hardener, just be sure you use hardener or it will take hours to dry properly.

The process here is the same as applying the paint, smooth even coats, patiently waiting for it to dry between coats and steel wool in between.

Now, here is another bit of advice that comes from experience.  If you are going to step away from the project for longer than 20 minutes or so and you have clear coat and hardener in your spray gun, empty it out and clean your spray gun with paint thinner thoroughly.  Because if you don’t you run the risk of the clear coat hardening in your gun, ruining it and much swearing will follow.  Heed my words, don’t make the same mistakes I did.

2 coats of clear is probably enough if you like the result.  I may still go back and add a third to get a better shine to it, this is up to you.

Drilling Holes

This is the scary part I warned you about earlier.  Now that our spoiler is painted up we have to use it for what it was meant for, bolting to your trunk.

The spoiler kit comes with the mounting bolts and a paper template to make sure you get the mounting holes in the right spot.  I ran a bunch of blue painters tape down the center of the trunk lid, more than is necessary, the measured in 3 places to find the center.  This requires a tape measure and math, you can do it.  Once I have 3 dots in the center use a straight edge to draw a line down the trunk lid on the tape with a marker.  You now have the center line of your trunk.  It should point to the center of your rear trunk emblem.  The template his a line on it for center, line this up with your line and loosely hold it in place with painters tape for the moment.

The mark for the center hold on the template will show you have far back it has to be from the forward portion of the trunk lid, measure appropriately and hold it in place with the painters tape.  For the holes on the outer edges measure to make sure each one is the same distance away from the edge of the trunk lid, and again hold it in place with the painters tape.

Use a center punch to help make sure your drill bits stay straight when you start drilling.  line up the punch with the marked center of the holes and give it a few taps with a hammer to make a small dimple in your trunk lid, no going back now.

To drill the holes start with a very small bit and work your way up until you get to the bit that is slightly larger than the mounting bolts.  You don’t want to start with the largest bit first.  I used 3 smaller bits before I got to the size needed for the holes.  You may need to drill the 2 outside holes a little bit larger to give you a little more room to work with when installing the spoiler.

Open the trunk lid and pry out the plastic plugs that hold up the liner and you’ll be able to see the light shining through your freshly drilled holes in your previously pristine trunk lid.  There is a roll of weather stripping that comes with the spoiler kit, be sure to apply this to the bottom of the spoiler before mounting.

Get somebody to lend you a hand while you have the trunk lid half open looking through at the holes and try to get the spoiler lined up.  I started with the center hole and only loosely fitted the bolt, then loosely fitted the 2 outside bolts.  Its a tight fit so some ratchets that angle are nice here.  Once you have all 3 bolts in, tighten them snug but be sure not to over tighten them as you could crack the spoiler.

And there you have it!

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Posted in DIY How-To, Saab
2 thoughts on “Painting and Installing a Trunk Mounted Spoiler


    Great job !!

    I have bought an original SAAB spoiler for my MY2009 93 conv.
    But it was not delivered with the mounting Template.
    Where do you think I can find it ?

    I think that my Saab dealer sell it only with the spoiler.
    Thanks a lot for your answers.


  2. Stephen Gray

    I don’t know where or if you can get the template by itself, but it should be pretty easy to make one. If mind didn’t have one I was going to get a roll of paper, secure it to the bottom of the spoiler, then make a rubbing on it using a crayon or a pencil. As long as the paper does not shift while you are doing it this will give you the exact location of the hold and the edge of the spoiler.

    Just make sure the center hole matches up to the center line of the trunk and that the measurements from the outside holes to the edge and lip of the trunk are the same on both sides.

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