Not sure about prices not being very different. Friend yesterday had a dash light on on his vw golf. Dealer: £75 to plug in their computer fault detecting thingy, Indy: £15. Dealer £96/h labour, Indy: £35.
The Indy is my brother in laws garage, but prices are his normal rates (he does ours for free labour). My husband has newish cars as he is a driving instructor and he always uses his brothers Indy garage for servicing (unless offered free at the dealersunder some kind of deal), never had any problems with warranty claims. Indy garage just has to do the work according to manufacturers schedule and use genuine parts etc etc. he also stamps the book.
I also think that the dealers’ so called mechanics are not always that good. My brother in law started his career at a ford dealer and in the workshop they got paid per job. The quicker they did the job (many corners were cut/left out in the process), the more they got paid. He was the only one doing a proper job/willing to take on more challenging jobs and earned the least money. He left and set up his own garage. He has a guy working for him and an apprentice. Most well organised garage in the city, party due to his mild OCD, you could eat of the floor in his workshop!
Good Indy I’d say, but get one recommended as there are a lot of cowboys out there.