So after two years, are you still on the fence? Have you started any type of business yet and if so, is it going well?
I personally do some mobile jobs, but prefer to do the work out of my studio (Garage

)
As you stated above, no overhead, clients don't mind, as a matter of fact they are almost more comfortable as the car is never left alone if its a several day detail.
The only gripe is that some seem to feel that no shop is the indicator of shoddy work, but once they see past projects, they change their mind.
For marketing, I have tried lots. From paid ads, to flyers etc. When I ask each client where they heard about me? Google places. The free, 10 minute setup Google listing is what brings me 85% of my clients. Word of mouth is the other 15%
This is what I am sticking with. I love working out of my garage as it is nice and easy to get up and start working in the AM. More time to spend on the cars IMHO.
Neighbors don't mind at all as I do not have a stream of cars coming and going all day. Its one every couple of days so its no biggie.