I don't know about the installation cost. I'm pretty good with mechanical things, never worked on turbos on imports, only turbo diesels such as cummins, powerstroke and duramax. I can't imagine it would be that much different but at the same time I know how picky these cars can be. Looks like I might be picking up a 535 this weekend. I've been on the car search for months, I've just been really stuck on weather I wanted a 135, 335 coupe, 535 or a 550. Looks like I finally made up my mind.