I had a 2 wheeled waste water tote once. I even used it; once.
Then it sat under the workbench out in the shop for about 5 years, then I sold it in a garage sale for $15.
Y'see, after I bought it, and used it once (at home), I realized that anyplace we went either had full hookups or no dump station within 10 to 20 miles.
So, for us, the fool thing turned out to be completely useless. I will never buy another one, two wheel or four wheel.