I noticed from your post that you're from S.F. There is a newer National Car Rental office on the corner of Mission and Van Ness in the city.
It appears that they rent BMW's, as they lot full of more unusual rentals - Cariolets, new VW Bugs etc. Just read in USA Today (Friday) that the new 3 series convertible is the best of all time, however, the 2001 is suppose to surpass even the 2000.