Autos are going to be in the culture for a long time and they will always need repair. If your shop has the right equipment and technicians who have the knowledge and guidance to do a good job, you will be successful.
Consistently keeping in-tune (an intentional pun) with the changing technologies is a necessity. I also think that one of the hardest things is to maintain good, knowledgeable technicians who will show up for work.
The backing of a good franchise can help with a lot of these issues, but it will come down to the example you set. Much god luck to you!
Thank you all for your great wisdom and sound advice!
I sincerely don't know what I would do without the friends at Freerepublic.