i have a vw caddy
400 lt tank fitted, i use approx 250 lts a day which to me is roughly 20-25 houses
i have a hole cut out in the passengers side bulk head for a one a clx18 and the other a slx35 and all the usually bits and bobs
all done diy, approx £500 to buy fit(youself) etc and i sometimes spend less than 10 mins on a three bed semi, regular clean