MY T reg migg has 100% me service now. so i have no proof BUT.....
i keep all my reciepts and a record of what has been done where and when. so that should i ever sell my baby....( cant see it happening) i can show the potential new owner its history.
my mother looked at my car folder and was gobsmacked. she has now done the same for their 2 cars and 2 work vans. everything is in date order and if its a reciept for parts i have annotated on the invoce the milage. or i get the VX garage to put the milage in for me when buyin spares.
Problem is.... I buy 4 x 5L oil, 3 x Oil filter, 3 x Air filter, 1 x Fuel filter, 3 x Pollen filter, all in one go... so yes I have the receipt for it all dated mid last year but the actual service schedule is down to whether the buyer believes my Excel spreadsheet...
well if they dont want to believe it then its their loss.! i would beleive it. cos im that way inclind
edit: What have you got on your spreadsheet?