looks like u just started with the car theme.

18 inch rims... i m not sure i understand your question... if it's your car, u are free to do whatever u want, as long as it's not ricey...

if u mean will 18 fit, then sure they fit. the question is, do u have the power to use that big of a wheel. if u remain mostly stock, just want the looks, 18 is fine until u want to race, then those wheels will drag u, not by much tho. i have like 205hp on the wheels, and i use 17s, i can use 18s but they will be heavy unless u get some expensive forged wheels.