There are still quite a few 1987-91 Camrys on the road. Here's what I've done so far to mine, besides get general maintenance up to snuff, removing weight from throughout the car, checking tire pressure often and running the tires at max psi (35 on these dunlops)
Basic taped grill w/ logo removed for flatness-
Taped the headlights too, for now. Why not?
Bent required front license plate at angle.
Taped off some but not all of the hubcaps for Extra Sexy.
Removed roof rack cross bars (heavy! well made!), put side-mount radio antenna all the way down, have Fastrak.
Folded passenger side mirror - car has excellent visibility all around with tiny pillars and large glass sheets. Only need the mirror when car is full of stuff - so not removing mirror entirely.
Changed one bulb from standard to led so far - every watt counts!
Doing P&G... not sure if it helps or not since I haven't gone through a 2nd tank yet after starting. Planning to put a "55" sticker on to warn folks. After taping the grill, the radiator comes on slightly more frequently.
One addition which probably hurts mileage are the rain/wind deflectors... I always wanted those when I saw them overseas so when they became popular in the US last year I went out to get some.
Next on my list...
- remove cargo area carpet
replace window motor - basic maintenance, not aero
replace burnt out license plate bulb
add valence air dam in front from a junk car lot or get lawn siding from the depot
add turbulence reducers(?)/ wheel blocks and tails
add a kammback
add side skirts using lawn siding material
add rear wheel well skirts
add front wheel well reduction piece
look for a prius or other newer spare tire that weighs less
add belly pan
build a "whale" rooftop shaper to work in conjunction w/ a kammback
hook up mpguino unit
replace front carpets with lighter material that doesn't skid but also protects base carpet. (towels w/ velcro or some other backing?)
LRR yokohama orange tires
polycarbonatize grill block, etc...
Am thinking of building a snap-on "kit" of ecomods for ppl who want them but don't have time to DIY. Not sure what demand is... I don't think "eco" or "money saving" is what will propel them though for most "consumers."