Couldn’t put it on the roof? I saw a wagon once with a chest freezer strapped to the roof and couldn’t stop laughing.
U-Haul is a titan of the moving industry, but it’s still surprising how few people would consider an occasional rental, be it a trailer like you used or even a truck, as part of owning a regular car. You spent around $100 to rent that trailer for a day? Imagine spending quadruple that - every month for a decade - just to ensure you have 24/7 access to 24 square feet of cargo space. Not to mention double in fuel compared to your Jetta.
Even ignoring the renting aspect, pretty well everyone knows a couple people that already have a pick up truck. Just borrow it for a day or two when you do a project or buy a new stove, fill the tank, and buy them their beverage of choice. It’s not complicated.