Quote Originally Posted by 3 Sheets To The Wind
No, the limo driver/company will cut your balls off.

The driver's got a job to hold down and I don't think he'd like some stoners tokin' up in his limo that he has to keep clean and stuff... he'd get fired if they found anything to tie him to letting you toke.

The amount you tip really goes by how long the drive is and how long you commission the limo.
Also, if you are of legal age, most drivers won't care if you take a couple of hits. It totally depends on the driver. Be very friendly to your driver.