We hired a Chrysler 300M (the new big chunky shape) from Dollar (via Airline Network in the UK)- got it for £28 per day inc all taxes, insurances, and fees
3.7L I think but not that powerful but a very comfortable car that turns a few heads - it has a presence copaired with British cars!
Build quality wasn't too great (gaps around the lights, Carpet cut too short, bare sharp metal in the boot etc) - but for that price and that overall comfort we thought it was a bargain - did us fine through California and Nevada!