On the other hand, you have Pagani's Zonda R, Lamborghini's Murcielago R-GT (and various GT-class Gallardos), the Ferrari owner-races, FXX program, and extensive participation in GT-class racing. Or Aston Martin, with cars for every single GT-class... Yet those are somewhat-covered with the RaceAbout, FZ5 and FZR.
Quirky stuff that actually is raced would indeed be a great addition - something like a Fiat 127 for Bump & Jump style races, or lightweight, underpowered sportscars resembling various UK products of the '70s for Historic racing - Cortinas, Elans, Imps.
However, Prototype racing is yet unexplored by LFS (though I doubt it'll be popular, considering those are 600hp monsters that still produce somewhat-limited downforce compared to single-seaters - should be as easy to drive as the FO8, I'd guess. But a '70s Porsche 917 lookalike, or the Renault-Alpine A442, would bring on a whole new kind of racing.
I encountered the same problem described above, and indeed - the 2.0 Alpha fixed it. Almost.
Some characters (I think color-changes?) still mess it up: I can't join CTRA servers, for example, because of the color-coded letters. Any way to fix those?