The stock ATS looks sporty for a cadillac but it doesnt cost much to spruce it up a bit more. I added a rear spoiler, body kit, and some badge work all for around $500. I’m trying to retain some luxury aesthetics without doing wheels. I actually like the stock rims but I got rid of the hard riding run-flats when I first bought the thing and put real tires on it.
Spoiler
Added a rear spoiler by Ikon Motorsports via Amazon for $70, however I dont see them in stock atm, ebay has them and seems that prices have doubled. I got the primer black version and spent another $150 to have a body shop paint it gloss black w/ clear coat. It’s held on by 3M 1″ molding tape. I de-badged it on the next section.
Before 
After
Badging
Also replaced the stock trunk badges with one Red and Silver Flex Fuel badge from https://rebadgedesign.com for $40. (I had installed a Flex fuel conversion kit previously) They have ones for the CTS, STI, and Cobra but not for the ATS so he custom made one for me and I got it in about a week.
I also replaced the chrome license plate frame with a plain black one because the back end just seemed to busy, trying to tone it down a little.
Before and After 
Flex Fuel Badge 
Flex Fuel Badge
I put a ZZP chrome badge on each door $14 delivered. It was hard to decide where to put them. Could have done higher up on the door or maybe fenders, but settled on the doors. As you can the new front lip/spoiler is on.
Front Bumper Lip/Spoiler
Installed the front bumper lip/spoiler $64 delivered from Amazon
Before 
After 
After 
After
Front Sidelights
Picked up a pair of White Sidelight replacements $28 from Amazon. I like the clear/white color better than the stock orange when they’re not lit. The white ones do turn turn orange only when they’re on.
Before After 
After
LED Headlights $60.00 Amazon
White LED interior light kit $18.00 ebay
Side Skirts
79” Side Skirts Extension Body Kit $65 Ebay. There’s quite a few sellers for these. At first I tried KGSplitters which were $160 but they had a coarse-filed matte edge, and just a black vinyl strip that barely covered the visible part of the top, just horrible. These glossy cheap ones are the way to go and look so much better (and easy/cheap to replace if they get damaged).
