Suspension is a great start. Lowers your car down to give it that "ready" look, and makes it so much more fun to drive even though it doesn't add any power.

Fo' Sho' mods: New shift knob, e-brake handle, pedal covers, sylvania silverstar bulbs, and maybe paint the brake calipers. Use the Dura-Color brush-on caliper paint for that.

Cheap performance mods: New air intake (short-ram or cold-air, short ram is cheaper and gives off a real neat-o sound, should be a snap to install), header/cat back/muffler (makes it easier for the engine to get rid of nasty exhaust, increasing power, no sense getting just one--gotta get all three).

All that should be more than enough for a 16 year-old. Especially if his parents don't spoil him rotten.