I had a similar situation with my 3 series. Had to have 2 new doors and paint. About Â£1800 of damage and nothing was recorded, nothing showed on hpi.
I think it's only when it's a cat d or above its registered..
Oh and no it didn't affect resale, just make sure it's a top job. The only was you will ever tell is with a paint depth gauge and most normal people carry them :-)
MG/SS M4 ZCP on order (build week 28)