A lightweight driveshaft is a nice since it is rotating mass, some companies claim up to two tenths quicker in the quarter mile. I think steeda sells a lightweight radiator support. Light weight wheels tend to be expensive. BMR sells lighter A arms, some people like them a lot, some people tend to be concerned that they are for drag racing only and will not stand up to hard cornering. The stock front seats are pretty heavy, you could get some Corbeau seats. To shift some weight off the front end you could get a battery relocation kit.