Well, I went down to this place earlier this afternoon to check it out.
It seems completely legit TBH. They're just one of those outfits that ship stuff in and ship it out quick (or that's their intention) with zero/minimal customer support post sale.
Basically, it seems that they want you buy the car 'as it is', hence the low prices. The one thing that seemed to connect most of the cars is that none of them are what you'd call 'Grade A' examples. Most of them didn't have a service history, others were marked, some with bits missing, some in bad condition etc.
For example, there was an Alfa Romeo that wouldn't shift into 1st or reverse, had an engine that had bottom end knocking (though at the time of this post there's some idiot on Ebay who's just bid £2,000 for the car, even though with those faults its probably worth no more than £500). There was a Golf GT that had no history, but was otherwise unmarked and the engine sounded pretty sweet and probably would have been a good buy for £5k. There was also a '03 A4 TDi 130 with the sports kit which looked in superb condition as well as a whole raft of faded 'luxo barges' and other bangers. Some good prices there though.
It seems that they have quite a few people on Ebay bidding on their cars but not following through with the transaction for whatever reason.
Overall, it seems like a straight up place provided you're prepared to take any car you buy as you find it, correct any faults yourself and not expect any after sales / warranty etc. Bit like an auction really.....