well at the social club you can download paper craft textures to print and make your own CTW models, i downloaded some a while ago but haven't touched em.. thought the other day i might try modeling one using the texture.
It's actually much more complicated than i was expecting..
anywho here's a screen, it's visually done but.. needs a few little tweaks before i stick it ingame, i MIGHT think about making a PC CTW mod for LC.