Unfortunately I have been to this place twice and didn't learn my lesson the first time.
I initially went with a water leak which they said they knew exactly what to with but found no fix which he charged 70 pounds for.
I then went for a service which I understood would come out at around the 200 mark which was substantially increased with lots of charges that hadn't been explained to me. He was quite aggressive when I challenged him.
I would be very cautious about this place.
RGA Porsche Centre specialise in servicing Porsche cars. They also sell related car parts.