you havent payed any AP you have paid the dealership a deposit and that is at the discretion of any Terms and Conditions as set by the dealership and nothing to do with motability , with reference to insurance that is something you will have to take up with RSA as its on one to basis as All situations can be Individual, without knowing the exact ins and out of your situation it would be unfair for the Forum to comment as in these circumstances as its down to how Motability and RSA interpret the use. your first call should be RSA to establish if you would be covered, that will then help as to decide if you should cancel or not. good luck.