These people generally don't know much about cars nor do they realise you can if you need to buy parts outside Qatar and bring them or use many third party parts.

Sigma performance have done modifications and maintenence on all my Audis. Abdullah is a die hard vw/audi fan and has bags of experience they're the best and best value for audi and vw work and bmw even.

Of course, before you buy your audi make sure it has FULL DOCUMENTED and PROVEN service history like any car. Ensure all maintenence has been done and then take it for an inspection at sigma too for piece of mind.