I need to change my V5 because I swapped the original engine with an other one. Also changed the color of the car. Because I'm from the mainland I need someone in the UK to do this for me. Does anybody know a (reliable) company who will do these things?

The only place to do that in the UK is the D.V.L.A. I am guessing that your details on your V5 are for an address in the Netherlands. If this is the case then simply correct the V5 or submit another on (pdf's available online) and they alter the details and return it to you.

Asking someone over here to give thier name and address for entry onto the V5 would be slightly breaking the rules, though if that is what you're asking where do all of your speeding tickets go? I doubt you would get someone to do this... for obvious reason's.

If all you require is detail change then the first paragraph would suffice...

Isnt 'V5' a DVLA cade and hence UK specific?? i assume this means your car is UK registered although located / used in netherlands. Is it currently registered in your name to a UK address or Netherlands address?

Daft question - can you not just send the document yourself to DVLA and ask them to return to Netherlands - just tell them you are working away.

Im puzzled as to what you are asking and why???

I bought the car in the UK and I've rebuilded it.
I just want to change the V5 so I can have it imported in the netherlands with a dutch registration.

Id suggest phoning the DVLA and get their advice. Your problem might getting to speak to the right person to get the right advice. If you are told something that doesnt sound quite right keep asking. Try looking on the website as well.

http://www.dvla.gov.uk/

Import it and change the details at the same time/after.

Why.. The registered owner can live anywhere... and use the vehicle in the UK.. seems reasonable to me.

However I agree.... speak with the DVLA. they should know!.