VAT refund

VAT that can be claimed is only for goods you take with you. Rental cars are not allowed.

From autoeurope:
What you need to know: VAT (or Value Added Tax) is a standard European sales tax that varies among different nations in Europe. The minimum allowed VAT rate is 15%, but individual countries can set their rates higher, and some will charge up to 27%. You will have to pay VAT on your rental rate (whether or not it is pre-paid), as well as any other extra equipment charges or local fees you are charged for at the rental desk, including one way fees, insurance costs, and location surcharges. Unlike VAT tax paid on goods, clothing, and souvenirs, which can be reclaimed at the airport upon your departure, you cannot reclaim any VAT taxes you pay on a car rental.

Thanks, your response was all I needed to know.

throughout Europe (not the UK) VAT can be reclaimed on unused goods removed from the country before use.

Services also attract VAT and that is never reclaimable, nor on any products used before departure.