after working out all the costs and using the exchange rate as £1 = $1.5 a good rule is the sticker (windscreen ) price in $ is what you will pay in £. works through out the range cheapest to dearest the extra value is VATable. my firebird was stickered at $4400 by the time it was MOT'd and road legal it worked out at £4500.
one way partially around this is to agree a lower price on the bill then pay the rest on credit card, I agreed $2500 billed the rest on card, the import duty and vat was calculated on $2500, you do have to realise that for insurance you can only put it down as the lower figure .
if parts are what you are seeking allways try and get them sent DHL, Fedex or courier as they send straight to you, if you use USPS they work with Royal Mail, your parcels get delivered to Mount Pleasant Customs office , not only do you get the delivery taxed but the pleasure of the £8 forwarding charge. Ive had the tax returned on proof of a lower price but seemed too much bother to then have to get the £8 refunded!!