I'd recommend an adjustable one if you are going to be attending track days so you have the option or adjusting it if needed. Most people just leave it on the middle setting and forget about it. The whiteline rear arb's are prety easy to install. Only annoying thing is that you have to drill into the chassis rails with a fairly big drill bit. Other than that its quite easy to do. just assemble it off the car to check if all the parts are there.(mine was missing 5 nuts, 4 washers and 2 bolts) Oh and I stress "USE GREASE ON THE BUSHES" i didnt when I installed mine and it made horrible squeaking noises on practically every bump. Ill try find an install guide i saw somewhere