Okay, is this just me or do others have the same experience?

When I go to book a typical 5-day rental, the price difference for Subcompact through Full Size are all less than $20 for the week, then the price for a Premium car jumps up to maybe a extra $50 or so, then another $80-100 for a Luxury.

My question is why is there such a big jump in price from a Full Size to a Premium? Does a Taurus really cost that much more than an Impala?

On the same topic, what exactly is a Premium car? Is this a classification that Avis and other rental cars have come up with? Honestly, I'd call a Taurus or a Lesabre a full-size car, but I guess that's just me.

Does Avis or (anyone else) have a listing of all the cars and what category they fit in?

I really do like the XM radio a lot and I would rent a Premium Size car more often just to get the XM, if the cost difference from Full to Premium wasn't so much. Though I see now that they Avis is now advertising XM only in the Luxury models. Does anyone know what's up with that?