If you take official Porsche parts to a reputable garage and get them to carry out your service, there is no reason why you will not receive the same quality of work that will keep your Macan in good health.

However, in terms of the value of the vehicle, a full Porsche service history will always be more reassuring to a private buyer than a full set of stamps from a regular garage. It's impossible to put a value on this, but it is a judgement you have to make. Alternatively you could seek out a Porsche specialist, who have a good chance of being cheaper than a Porsche main dealer but will offer almost as much reassurance to those who recognise the value of independent specialists.