Does this modern mobile calf-catching cage qualify as a sidecar? Not really, I guess but close enough.
I happened upon this magazine, one of several of its type apparently and it appears that farm machinery is the last bastion of small fabrication shops. There is an endless of array of products from small companies, bale carriers, fencing, cages, tillage implements, etc.
I picture a land of farmers getting creative, designing and fabricating some device that makes their life a bit easier, then deciding, hey! maybe someone else might want one too.