First thing I did was a set of molded floor liners. Weathertech is nice (had them in another car) but I bought the Husky Liners because they cover more of the dead pedal area and were cheaper. I also have the matching rear liners even though nobody ever sits back there. Tinted windows look great as an exterior cosmetic mod, but are a must for increasing comfort in hot weather. I also swapped out the shift knob for a satin silver cue ball type, but there are tons of options there. I also installed aluminum pedals which I love what they do for the feel of the clutch engagement and the larger surface make heel-toe shifting easier.
Cosmetically, the thing that drives me nuts the most about the base trim interior is the totally drab, all black door panels. The premium cars have the chrome door handles and chrome trim ring around the woofers that aren't even in our cars. I wanted a little contrast to make the doors pop. I bought a set of chrome billet vent covers for the little defrost vents and some polished stainless trim for the door lock bezels along with some satin door lock knobs. I bought some satin silver 3M vinyl to attempt to match the satin silver trim on the steering wheel and tried to wrap my door handles, but they looked bad and the color didn't match to my satisfaction. Instead, I am going to buy a set of door handles from American Muscle or Late Model Restoration that are now available in satin silver. That should finish my interior off...I hope.
Door Lock Trim:
Door Panel Overview: