Although Batman has always been the same millionaire-playboy-turned-crimefighter since his inception, the Batmobile has definitely changed with the times—and remained stylish in every era. Want proof? We have it.
The Batmobile has a few characteristics that remain more or less constant: It's black with fins, and it looks extremely powerful (although it would make parking in Gotham a logistical nightmare). It's also reasonably expendable: Bruce Wayne has changed his wheels more often than he's changed his iconic suit.
According to Autoblog, "[D]id you know Bruce Wayne's secret identity spent some time behind the wheel of a gussied up Ford GT90 Concept? Neither did we. How about an Opel Speedster, Dodge Viper, several Chevrolet Corvettes, and a Mercedes-Benz CLK-GTR? Yep, we had not a clue."
Thanks to Autoblog, who had help from designers at BatmobileHistory.com and researchers at CarInsurance.org, here's a look at all of the Batmobile's incarnations. (You can view the full-sized image at Autoblog.)
As a side note, BatmobileHistory.com, the gold standard of Batmobile lore, has a picture of H.R. Giger's version of the Batmobile, which ultimately was too visceral for Batman Forever. It looks pretty much as you'd expect for a Giger-designed Batmobile.