Yes, I too had this letter and after a few enquiries discovered that DVLA do audit registration data with manufacturers from time to time and that in my case the error was due to a transcription at DVLA misreading a "5" for an "S". I also received an amended "European" style registration book the V5 (ie red now not blue), however what has not been mentioned on these posts is the MOT document which, due to the DVLA records error, also appears with an incorrect VIN number, although all other details (reg number, chassis number etc.) are correct. When I checked mine and realised I had the same error on my MOT certificate I had to contact the nearest VOSA office, arrange to go to them with my documentation, and they amended the electronic records and issued an amended certificate at no cost. I would urge anyone who has had this log book issue check their MOT document for this. Interestingly the MOT stations are required to check all details before issuing a new MOT certificate, mine has had 4 MOT's and all went undetected until now !!