I didn't tip the ME driver in May when he brought us back to the airport. Why? Because we had my MIL in a wheelchair, my step-son in a stroller, and about 7 bags and he dropped us off on the bottom of the garage informing us the bus was too heavy to go up to the 2nd level. We got no assistance from anyone in carrying everything inside. Now, whether or not he was telling the truth, I felt no need to tip a driver who just dropped our bags and left us.