[ergonomist]

Just dug out the Ts and Cs when I bought my XC90 (I know - a bit sad...). My guess is they're pretty standard for any dealership. There's a clause that specifically allows the dealer to pass on any increase in VAT rate (and it's not a reason to cancel the contract).

Additionally, there's a clause that covers changes in the 'Manufacturer's or Concessionaire's recommended price for the goods' - which would include changes arising from changes in duty. This clause allows the purchaser to cancel the contract within 14 days once notified of a price change, if the dealer chooses to pass on an increase, or if there's been a reduction (as if!) and the dealer chooses not to pass on the full amount of the reduction.