I recently took delivery of a Volvo with a lot of extras all were priced to myself minus the 20% VAT. I was surprised at the time and didn’t make any comment, and I am obviously not complaining now lol.
The 20% would have been a straight discount Crusty, it’s just coincidental that it equalled the same % as VAT. It is commonplace for dealers to offer 15 or 20% discount off optional extras.