I know the OP is not considering early termination but something came to mind today because It’s not just about the AP though because under the HMRC 3 year rule introduced 1st April 2017 you can only acquire another car with VAT relief if you have a change of disability condition or the car been lost/stolen or written off by your insurance company.
Just been doing a little reading up on this today after her in doors told me about the BBC Fraud Squad program today where a family of fraudsters were ripping off the taxman a million in VAT fraud on disabled buyers adapted cars, not Motability cars I quickly add. ?
To much to go into here but you can catch it on the iPlayer, select today program of “Fraud Squad” and go forward to 34m 30s to miss the none relevant stuff.