Climate changes affect your skin cells. Causing them to fall off rapidly. So when you apply your lotion at home then get into the car your skin cells are falling off. Also, part of the reason that tanning lotion works is because it is making your skin moist. But you applying it at home your skin will absorb it by the time you get into the bed.
So just a little info for you but you want to apply the lotion immediately before tanning, like it says on the back of the bottle.