joanod,
hate to burst your bubble, but it seems that the V5 document is required to be in your posession when you are registering the car here in Ireland.
On boards.ie, I found a link to an Irish site that was set up to help people when importing cars from the UK - there is an article about a missing V5 document - [broken link removed]
( read both articles on the page)
By the way, even if the dealer says he doesn't normally give the V5 document directly to customers, but sends it to the DVLA instead, then how does he even propose to even send it to the DVLA if he hasn't got the V5 document in the first place????
teddyk.