My reading of the policy is that any servicing or repair work not carried out by a vw dealership must comply with vw schedules and use vw parts. My independent garage includes part numbers and/or specs such as oil used in the invoice so provides proof of compliance with vw schedules. This would appear to meet the all-in contract requirements but I would double check with vw and is in line with the requirement to meet the initial 3 year manufacturers warranty.
Vehicles have to go through a free eligibility check at a VW dealership before they are considered eligible for the All-in product. I dare say that if servicing has been carried out by an independent VW specialist, then checking the service history to ensure the work was in accordance with VW service schedules would form part of that eligibility check. This being so, it makes it very important that any invoices for work carried out by a VAT registered independent VW specialist fully documents the parts/fluids used, along with part numbers, and VW spec numbers for fluids.
Seat has its own Seat branded All-in product and I read on a Seat forum that if any of the advisory maintenance work such as an air con service had been missed, then the vehicle would be ineligible for the All-in product until those missed jobs had been carried out by the seat dealer. The recommended (as opposed to required) biennial air con service is one of those jobs that some owners may not have bothered getting done, especially if the air con is working effectively (if it ain’t broke, don’t fix it?) and is considered by some to be a bit of a money maker for the dealer. Assuming the same approach to missed work is applied by VW, then the additional cost of getting these jobs done need to be factored in by owners considering buying the All-in product.
The All-in product excludes vehicles that have been modified, but I’ve read on other forums that some vehicles with modifications may be eligible - more likely to be those with cosmetic modifications as opposed to performance mods.