Why can't i buy VRP's using Paypal in the UK, no matter what I try, it just wants Sage pay and my credit card details
Cant tell you, but you can, alternatively, use your Steam wallet for buying stuff. The VRP system did not work for me years ago, too, though I do not remember the details anymore. I then stopped messing with it. Life's too short.
I had the same issue, use this address: https://www.raceroomstore.com/shop_en/ Make sure your Region (top right-hand corner) is set to International.
When I pay with card, it says that the payment recipient is directly KW Automotive GmbH. So not even some middleman company. I'd trust that.
Jacob above was correct, if you set the store region to "International (English)" you should be able to check out with PayPal.