http://www.falkirkcarcarriers.co.uk/
Used them to transport my TVR down south. Very reasonable price and there were no issues.
Make sure you mention it's a low car (if appropriate) - there was a small surcharge for this.
Falkirk Car Carriers
Re: Falkirk Car Carriers
I used these guys to transport my atom from Inverness to Somerset. 600+ miles for £450. They collected and delivered on time and as promised. Your car will sit on an uncovered trailer with several other cars and collection/delivery is a few days apart (Friday/Tuesday in my case) so if you can live with that they offer good service and value for money.