I have little suggestion. Add fixed Super GT, Uranus and few more vehicle to CUSTOM.IMG.
One of my friends
FireBox fixed almost all SA vehicles bugs, including missing speculars, missing tuner decals etc. I think he wouln't mind using these.
I mean,
of course You can do it individually if You want, but how about adding it just as deflaut, so less acknowledged players (coz not everyone is really skilled enough in GTA3.IMG editing) can have it fixed in SA:MP by deflaut.
Also... maybe adding 2 beta Elegy paintjobs by deflaut to Custom.IMG aswell, one for Elegy, other one in Jester.
Rename legend2.txd to jester4.txd, legend3.txd to elegy4.txd and put to CUSTOM.IMG.
I know they got messed up parts, but even I can fix it to add 'Alien' and X-Flow' logos on windows cover like usually paintjobs have.
Adding this to Custom.IMG would make it easier for ppl who just installed SAMP and dont really wanna install mods, download some mod installers or so. Just quicker for easy start, without messing in GTA3.IMG.
Also, multiplayer adventage of this as deflaut to CUSTOM.IMG is that every player gonna see it, not just ones who individually installed/edited GTA3.IMG on their own computers only.