Hi,
don’t want to be a smartass, but as far as i know alloy wheels are usually made from aluminium, not steel.
But what really bothers me is 4 stacks of steel for 1 single wheel?! I guess the car weighs more than 4 tons when its done 
Jokes aside, is there any balancing planned on production quantities? Like 1 stack of steel produces 10 steel panels or sth alike?
Yes, it’s the same for Tyres, the animation suggests that you get 2 tyres at once, but you only get one 
Not sure if that’s a bug or more of a suggestion really but I get the point you’re making.
I think a regular (steel) wheel as a spare wheel is correct, most of the time it is one.
My car had an option for a “full replacement spare wheel” so it is alloy.
Making alloy wheels from steel ist not exactly a bug, maybe only an inaccuracy.
Rebalancing the product outcome would be balancing, obviously 
Its an interesting point actually, because we already have aluminium in the game, so it might be an accuracy and a decent balancing thing to change that. I shall investigate
Actually the more I looked into this, the numbers for wheel production did not make much sense, in terms of ensuring you can profitably make them (or at least not lose a fortune!). So I made some changes: