In addition to this "contractor card", I "rented the vehicle", and "sold the ice cream" to the driver.  It made for a cleaner understanding of what was expected.

Vehicle Rental

The Vehicle Rental was paid in advance (from the previous day's work). This was a small amount ($25.00) that was waived if certain criteria was met.  We basically rotated the "rental" throughout the season.  This could be given out as a bonus for those who worked through the end of the year.

Buying the Ice Cream

Every driver left the base with a standard load.  When they arrived back to "base", we would count their remaining load.  The driver would then buy the ice cream that was missing from the original load.  If a driver wanted to give some ice cream (melties) away, or make deals ... that was fine.  They simply paid me for the ice cream that was missing, and they kept all of the rest of the money.

I would also give them "discounts" on the price, based on how high their sales were.  I explain that on the "incentives" link above.