Vehicle ownership documentation?

I bought a Citroen Xsara Picasso in a private sale.  Saw it posted for sale on the side of the road, called the bloke and went and looked at it.  It drove well and our mechanic said it was in OK shape so I bought it.  I signed something with him that he said he would send in, and gave me a part to keep showing that I had bought the car from him. 

Yesterday in the mail I received my V5C.  It's red on the front and has a blue bar across the front stating:

THIS DOCUMENT IS NOT PROOF OF OWNERSHIP.  It shows who is responsible for registering and taxing the vehicle.

Inside it has my vehicle details and places to sign if selling the vehicle in the future.

If this doesn't show that I own the car, what documents ownership (i.e. the equivalent of a title the US) here in the UK?

Helpful information here:

http://buyerbeware.direct.gov.uk/index.html

From their checklist: "Can the seller satisfy you that they own or have the right to sell the vehicle? e.g do they have a bill of sale/receipt?"

There are online/SMS services that will check for any outstanding finance on a vehicle as well as if it's been an insurance write-off, milage discrepancies etc, if you're spending a decent amount on a newish second-hand car it would have been wise to use one of those since there could be outstanding finance on it.

David.

I used one of those services--HPI.  The check all came back clean.  My question is, is there a document that I'm supposed to recieve other than my V5C that shows that I now own the car in question?

No, you won't receive anything other than the V5

No, you just get the V5 (log book), basically what it's saying is a disclaimer. For example if there was finance outstanding on the car and the previous owner hadn't payed it off it could be repossessed by the finance company, and you being able to produce the V5 would not alter that.