If in doubt ring up Insured warranty and get them to send you a confirmation email re servicing and validity of the waranty
This is the respose I got -
Thank you for choosing to purchase BMW Insured Warranty. Following our recent telephone conversation, this email is to confirm that in order to keep your BMW Insured Warranty policy valid, all service work must be carried out in accordance with the manufacturer’s specifications.
The full manufacturer’s specifications can be found in your vehicle handbook and these would include having your vehicle serviced at a VAT registered garage whilst only using genuine BMW parts. Proof of your service may be requested at the point of making a claim.
Please note all repairs must be completed by an Approved BMW Dealership.
If you do have any further questions or queries please do not hesitate to contact me.
BMW Insured Warranty Services Co-ordinator
BMW Insured Warranty Services