The European Commission on the date of July 31 2002 published Regulation 1400/2002. One of the objectives of this regulation is to prevent the monopoly of official dealers in respect to revisions of the vehicles within the period of official warranty. The Regulation 1400/2002 provides that the consumer is free to go to any official workshop both as an independent to make necessary revisions to your vehicle.
The consumer does not lose the official manufacturer’s warranty not to perform an official revisions Workshop brand. But yes will be cause for loss of official warranty conducting a defective repair for part of an independent workshop.
As for spare parts the consumer can use any spare in their revisions as and when meeting the requirements established by the manufacturer but may not require the use of a number of specific brand as a requirement to preserve the official vehicle warranty.
In short the consumer does not necessarily lose the warranty on your car because the maintenance of the same be made outside the official network of the brand. Fundamental is always that the official manufacturer’s recommendations and that the parts used in interventions are original or equivalent quality.