Finally got my mobile wash setup rolling

Did the same thing with one of those three shelf carts a couple years back and it's still my favorite garage purchase. Mine lives in the corner with all my wash stuff on it, foam cannon, buckets on the bottom, chemicals in a little caddy on the middle shelf. One thing I'd add is a magnetic parts tray stuck to the side, cheap and perfect for clips and lug caps that always used to vanish mid-wash.

I also learned the hard way about caster quality. Mine had the hard plastic wheels that sounded like a shopping cart on any rough surface, so I put pneumatic ones on and it made a huge difference, especally on my sloped driveway where the cart wants to run away from you. For bottles I went the opposite direction from a rail, just used a tension rod between the uprights and hung trigger sprayers off it by thier necks. Takes up zero shelf space and nothing falls over when I'm rolling it around. Only real complaint is the thin steel shelves flex if you set anything heavy on an edge, so keep the gallon jugs centered. Good luck beating the freeze, my hose bib is allready getting shut off this weekend.

I went smaller with mine and skipped the water tank entirely. Once I loaded mine up I realized anything with real weight in it turns the whole cart into a workout on a sloped driveway, so I just run a five gallon bucket on the bottom shelf and fill it from the spigot when I need it. Empty bucket, light cart, and I refill as I go. The other thing that made a big difference for me was a cheap bungee net over the top shelf. Before that, every time I hit a driveway seam a bottle of spray wax would take a dive. With the net I can pile towels and bottles on there and nothing walks off. I did learn the caster lesson the hard way though. Mine came with those little hard plastic wheels and one of them cracked after a summer of sun, so I'd say swap all four if you're going to bother, not just the front pair. The back ones take just as much abuse, they just fail quieter. Mine mostly stays stocked for interior work now, brushes, APC, glass stuff in a door caddy, so I can roll it right up next to the truck and work the cabin without hiking back and forth.

Roll one of these full time for mobile work, did 41 interiors off mine last season alone and it holds up fine as long as you dont overload the top shelf. Two small mods that paid off: a cup of brushes zip tied to an upright, and a strip of electrical tape wrapped around the top rail so towels quit sliding off when the cart sits on a slight grade. Curious how the handle height works out for you, mine wrecks my back after a full day unless I park it downhill enough to bring the grips down a few inches.

Update: took the advice about the tank and swapped it for a five gallon bucket on the bottom instead. Whoever pointed out how heavy a full cart gets on a slope was right, my driveway tilts toward the street and pushing it loaded was no joke. Also zip tied a cup of brushes to an upright like the other poster mentioned and it's already paid off. Cart rolls free, weather held out, got the last wash done.