The model your are using is to simple. Since there is a shortage of new vehicles it pushes up the price of used ones. Then any supply of new vehicles that hasn’t been sold yet goes up. People will keep cars longer since the price of new vehicles has gone up. The drives higher repair rate of vehicles and parts prices will start to rise. Since there is a chip shortages you may not even been able to get certain parts new so it drives up the price of used parts containing the chips.

As people put off buying new cars when cars start becoming more widely available the prices stay higher until the shortage worked out and then prices of used and new car drops. Manufacturers are likely to overshoot the number of new vehicles since the models they are using assume the increased demand. This means once it is worked out a significant drop in prices and you can get vehicles really cheap. See 2008 cash for clunkers where it caused a spike in used cars price temporarily. It also had the effect that leases where cheaper since manufacturers believe they would be able to sale them used at a higher price which was only temporary causing them to lose money.

You do get increased prices for new stock that don’t have existing contracts. If you screw up your estimate of what you need and your suppliers don’t have the capacity to make your parts, now you have a shortage. Now you have to shutdown because you can’t get parts but a manufacturer who did a better job of estimating will be able to charge a higher price. In this case it would be Toyota which didn’t cut their chip orders when the crisis hit. Of course they are also likely to have some shortage of certain vehicles since there will be a shift in demand for their vechiles. So if you own work trucks the value of them will skyrocket right now since most of them in the US are made by the big 3 which don’t have the chips to manufacture them.