Do the trailer rental companies give you the WDH along with the trailer? I've never heard of renting a trailer before, so I don't know what they require you to do. You should just buy your own WDH if you intend to eventually. You'll probably find that it makes towing much more stable when it's properly adjusted, even on straight/flat roads. It seems odd that the trailer rental company would require you to use their WDH, but let you drive off without adjusting it properly. Though like I said, I know nothing about renting that sort of thing.

__________________
2003 3.0 5MT Topasblau
Purchased in 2016 and sold in 2024
2012 35d Platingrau