Hi we are going to majorca at the end of October - we havent booked the car as yet but will be doing thru carjet.com as we have used these on mailand spain without any problems and know of people using them from palma airport without problem.

To my knowledge they use cars no more than 12 months old and you reserve your car / booster seats online but they are paid for locally. They usually request that you fit them yourself though - i guess its to do with insurance.

hope this helps