On a recent visit to see the in-laws, I mentioned to Jan-Mark that I needed a facility to hold my fiberglass antenna rod vertically when doing mobile shortwave (the last time I tied the rod to a tree with zip ties, no joke!)
After a couple of months of careful design and build came what I dare to affectionately call "The Tank". a rock solid piece of pure stainless steel into which the antenna rod is mounted and where one of the cars wheels is used to hold it in a vertical position.
The thing works beautifully and can be collapsed into a portable unit which easily fits anywhere. The build quality is so sturdy that probably one day in a distant future archeologists might find it (stainless of course) and wonder what it was used for by humanity.
Oh yes, I had the impression by the way that my good Korean rice rocket lifted its front wheels a bit when the contraption is in the trunk :-)