I think that it would be so nice to have a button on the Stock Room GUI that allows you to delete models that you don’t produce anymore as it can become cluttered when looking on the “show out of stock models” page. Another thing would be to rename them?
Furthermore, having too many models becomes a problem when you’re trying to play like a company (giving them a similar name, model numbers, ect.) I notice this problem the most when I am building a new line and am running the game at the same time as the second you connect the stations to the stockpile they start to produce cars. this becomes a pain when you’re trying to add specific upgrades as the more upgrades you make post-connection = a new model = new name, which can be a tad irritating at times. To combat this, I suggest a way of either clearing a line to reduce the amount of models you create OR you could have it so you have to “open” a production line before it starts production.