personally i think they should make a transformer of the saturn ion, of course it not a great car, its not even a good car, but the real one has alot of panel breaks which would be very convenient for making a completely accurate body and itd be easier to do the bot mode with so many available panels
other cars i would like to see as transformers:
Hummer (the real one not the H2)
An old lowrider like an El Camino or Coupe De Ville
Jeep Rescue
VW Eurovan
boxy cars make better bots, im all about sports cars but the curvy body panels dont seem to integrate well as armor or body parts
that said, i would also like to see the 2 most angular of recent sports cars as transformers
Ferrari Enzo
Lamborghini Murcielago
and last but not least
1990 Acura Legend (my car )