My opinion (along with a few others who've already responded) is a 24' length is the best size to go with. I had a 28 and while the extra length was nice, it proved to be too long to get around in some tight spots. I found a 24' adequate in space and easier to manipulate in limited spaces.
I've not heard of the running straps from front to back approach. Would be curious to know more.
Hook up the front straps to tie downs, run them to the back ramp. Pull the car in, put in park. Put the ratchets on the front straps and pull the car forward tight against the park pawl ( I put the hooks on the rear subframe by bumper bracket, race car). Put the axle straps on the rear and pull the car back a little to release tension at park (watch the tire move). Don't cross them, as the pro's advise as well.
Your done, working with plenty of room on the beaver tail and ramp. Go under the car once, not twice. Of course unstrapping saves the same amount of trouble as well.
Best of luck.
