Detroit Auto Show: BMW 1-Series ConvertibleMike Spinelli1/13/08 2:33pmFiled to: Detroit Auto Show08 Detroit Auto Show1-Series128i2008 Detroit Auto ShowBmwBMW 1-Series ConvertibleDetroit Auto Show 2008ConvertibleDetroit18EditPromoteShare to KinjaToggle Conversation toolsGo to permalink Say guten tag to BMW's latest cabrio. It's the droptop version of the 1-Series that debuted earlier this year. We've already seen the press shots, back in October. But after all those months, BMWs come up with a suitable US base price of $34,000 to start. That's for the 128i; no word on the 135i convertible, which is expected in Fall 08. In other news, the back seat is the size of an infant's bathtub.