there is a limit and I think it's 6.
BUT it only refers to CGT - any more than 6 and you start to be come liable for CGT, which will only be a few percent - if they catch you.
Only 6 per year?

Looks like prison for me then
Ah then I'm already near that, I'm on my fifth car in around 12 months.
Not bought and sold for gain, I just can't make my mind up what I want or how many either.
But.....I'm already thinking should I have sold the TD estate, should I buy another Omega.
Anyway as the origanator of this thread it sounds like a right pita to actually buy and sell cars legally.
So how do all these ebayers go on, they're not all registered as traders surely. They must get around the registration docs somehow, without it showing as a new keeper, especially if they want to move them on quickly.
I actually bought one last year from ebay, the car was last owned by someone in Nottingham. The guy I bought it from was just around the corner from me, but he had the whole V5.
and kept the cars at his mothers house, sounds dodgy but he was actually a nice bloke.
Mick 
Traders often buy as if a private buyer and promise to send off the reg doc, then hold onto it and use the following to explain why it is not their name on V5c:
It was my late father in laws (would you check?!)
It is my sister/aunt/cousin/ex-girlfriend's car
a friend/someone at the office wanted my car and I took it as p-ex to help them
I was going to register it in my name but:
the child seat won't fit
my wife does not like it
I won another car on ebay at EXACTLY the same time
etc