Is this a good idea?

Or is it a "free rape" pass if she forgets to fill it out and the cabbie's a degenerate? Without a doubt.

Bad idea. Also a good idea (if the cabbie is swell and harmless). Not the rape part, asshole.

If you ever rape someone you deserve a dick chop that every scimitar in the land will be jealous of. If a girl wants to fuck you, she will and she'll know pretty early on. No amount of flowers, sweet poems, or money will change her mind unless she's a soulless fly trap. Who wants that anyway? Even if she does have a great ass...