I think the laws of physics are working against you. Shredding relies on high speed because of the nature of the work. A low speed auto accident merely makes dents. It takes high speed to disintegrate vehicles into unrecognizable pieces, which is essentially, shredding. Low speed "shredding" is called whittling.

Thank you Yardvaark for the advice. I will look for an electric one, but small footprint, eco-friendly, if possible ;)

https://www.lowtechmagazine.com/2011/05/pedal-powered-farms-and-factories.html

https://www.instructables.com/id/Quick-made-hand-cranked-compost-shredder/

Thank you Lady Driver both links are awesome! It is a great incentive to getting fit while saving the environment ;)

Last night, I found this link https://bestreviews.com/best-wood-chippers

Anyone has tried the "LawnMaster FD1501"?