I have booked in the car this Friday with the local Toyota dealer. I shall mention your response without referring to the sauce. When I get my car back I shall revert back to you with the result.
This sounds promising but I am no expert. I am OK with your comments as the dealer has already gone up different avenues and failed.
Thank you in the meantime and as I say I will get back to you probably early next week. The dealer is very likely to say he has to order in parts.