You don’t, cordless drills are completely useless.[/quote]
You can’t even get the damn batteries out of them 
Also for a solar car you need At least one storage battery, at least four solar panels (more=faster charge) and a large electric engine. That said gasoline is much better IMO, yes you have to find gas but for the most part once you’ve got it, it’s fairly simple to keep it topped off while driving around.