Originally Posted by Ag229487

I have an Infinit G35 coupe right now, good car, but I am planning on picking up a 545i hopefully next May/June (2007)- A used one probably with under 15,000 miles if I can find one-

My question is, what type of mods that wouldn't affect warranty, boost the HP to the most possible-

I looked at the engine tuning from Dinan and it looks like with intake, exhaust and something else its about 28 hp+ gain so that brings it to like 353hp total... I'm trying to get like 400 out of it, is this possible?

What type of mods have you guys done to your 5's that brings about the best results?