Obviously it's a play on the name of a famous muscle car (the Pontiac Bonneville) though it refers to neither muscle nor car, but a very stiff erection that steers its owner wherever it wants to go (to a nice warm parking garage of course).
A nightclub, bar or a part of town that used to be famous for being overabundant with good-looking women, but is now just full of sexually frustrated men looking out for said women.