Depends on what you're looking for...
Aftermarket parts are rare for the Gen 2 Solara ('04 - pres) but there are a few TRD things you can bolt on to help with looks/performance. FSTB, RSB, Springs, Muffler, Shift Knob, etc...
I have all but the springs installed now (plan on going with TEIN Coilovers), as well as an Injen CAI intake. There are also several HID kits out there available that work - just make sure its a high quality name brand (mine are McCullough sp?) and other custom things you can do to trick out your ride and make it special.
Good luck and have fun!