Does a rear spoiler make any difference in handling?

 

Help him please!!

 

A rear spoiler will not make a difference on a stock G35.

 

It depends on the shape and angle of the spoiler and the speed of the vehicle. The stock spoiler is unlikely to have any real effect even at high speeds and its nearly flat. A large, properly oriented spoiler (which looks pretty ricer) will generally start to have an effect at 100mph+ so unless you are doing high speed racing, consider it cosmetic.