I have the same problem as Hitman, a very narrow driveway leading to the narrow garage and I also have to reverse for about 20 yards. I read that the reverse gear action should not be used for more than 1 minute at a time so as not to overheat the components. Until I get a turntable sorted, I reverse mine half way out, then don helmet and gloves Etc. then reverse the remaining distance. Not ideal, but until I find or make a decent turntable, it will have to do.
A friend of mine made a crude turntable built into his driveway. He sunk an old scrap car hub into the driveway, bolted on a steel wheel, then a plate on top of that, surrounded it all with neat monoblock bricks and hey presto a working turntable for under £10. Only problem he has is the space filling with water, he reckons it would be easier to change the hub when it rusts rather than try and waterproof it. So i'm now thinking along those lines as well.