I would agree with Kev, start from the farthest point first!
If you are parked by one of these awkward accounts, draw out enough hose from the reel and walk up path or whatever access you have to the property feeding the hose out as you go and then work backwards.
For the next week or two I shall still be working out of the back of my car, though unlike yours mine is a hatchback.
But I also use my trolley, I have started putting my trolley on the roof rack
Not something you could do with an omnitrolley though
But it does mean I have all my bits on board so I can use the trolley when I need to.
But like you I am concerned about my back (currently having to put up with some sciatica, beginning to ease now thankfully) and my Dr has told me that if I continue working in the manner I am at the moment I'm at risk of back injury.
The continual lifting of water containers in and out of the car, and in particular over the tailgate isn't a good one for the back.
Ergo, today should see me finally order my van
I'm still going to have some 25l containers in the van, and still intend to use the trolley at times, but I'm also goinig to make up a trolley of my own as the one I have, though very good, has me twisted and bent over slightly as I wheel it around, so I'll probably make up a sack truck based, or buy one from the guy who has just started making them.
If I was in your position, and was intending to continue working from the car, I would fit a tow bar and get hold of a small/medium trailer, you could take more water and have much quicker access to hose and containers, plus you could always take your trolley along with you, a simple matter to drop the back of the trailer and wheel out your trolley.
Regards,
Ian