It never ceases to amaze me the legal cons these firms try.Upselling is the name of the game,there is very little return on basic rental income for these guys.I used to own a franchised operation close the MIA years ago and some of the stunts we pulled were sometimes beyond belief.

Selling windscreen ins,almost pure profit
Add.driver ins,pure profit
CDW (collision damage waiver) almost pure profit
Empty to empty tank. (no one ever bought brought a car back empty.pure profit on the fuel)
Buying a full tank from empty.As above
Selling the basic insurance package to foriegners.The vehicle was already insured,pure profit.
I'm sure breakdown cover was in there,again the vehicles were usually covered by manufacturors warranty or AA/RAC
I only ever had one customer,German, get upset and demand to be returned to terminal 1 so I dropped him at Terminal 2 for his troubles because he had pre booked another car,just in case.

Something to think about......