First thing to check is if you have a seal. When I purchased my convertible, it didn't have a front seal. On my first Woodward Cruise I had to come through a downpour. With no seal it literately poured in. Lucky for me I was smart enough to keep a towel handy.

That dollar bill test can be used on any seal. I remember the techs at the Saturn dealer using that to find side glass leaks and whistles. Thanks Daren for that reminder!