I don't believe this ****** thread. How old are you?!?! Seriously, you bought a car to get a girl? This was bound to fail from the beginning. It sounds like, the way you put it, that she asked what your after work plans were and such, that she was setting it up for you to ask her out. You missed that boat.
Now, she just started dating this guy, the world is not ****** over for crying out loud! It may not work out. And I'm not condoning going after taken people, but I think in this case, you sound really young, so maybe if you ask her out she may decide to take you up on that offer and you may hit it off and the other guy falls outta the picture.
And seriously, not all of the seemingly *perfect* girls are taken, handicapped, or psycho!!! I'm not saying that a lot of girls don't have issues, because yes they do, but not all of them. This is one stereotype I can't stand!
/end my rant!
So, basically what I'm saying is, grow a pair and ask her out anyways. If she says no thanks, move on. And if she works at this place you claim all the women are snobs, then how do you know she's not just like them.
(Disclaimer: it is possible, but VERY rare, that she may be lying about the boyfriend to see your reaction. See comments about girls with issues. If this is the case, you probably don't want to date her anyways)