To get a newer car would suggest you have one you are looking to sell (either private or P/X)... You do realise that this "crash" you are so keen to get may also affect your own car?
Wait for the March registration figures to be published by the SMMT and they will tell you what you need to know, obviously followed by April for a more well rounded picture.
Given the relaxation of MOTs for a while it'll mean people are able to hang on to their cars for a while longer assuming they are not literally falling to bits, this will have a knock on effect for both new and used markets.
And the above is only going to worse. After all, people aren't going to be able to buy a car from a closed dealership.
It's going to be a weird supply and demand situation. My guess/expectation is that there will be a big "glut" in cars.
Just as with houses, it all depends on whether the crash impacts the value of what you are purchasing more than the value of what you are selling. When people replace their car with something newer it nearly always means they are 'trading up' to something more expensive which then in turn usually means it would drop in price by more than the car you are selling drops in price, if they were affected equally in percentage terms.
Say you want to replace your £5k car with a £20k car. Currently costs £15k to upgrade. Now consider prices drop 10%. This means only £13.5k to upgrade.
Clearly it is a bit more nuanced than that dependent on what you are buying/selling especially if it results in a situation where you simply can't find a (sensible) buyer for your car, but a crash is great for most people because it means either you spend less money or you get something better for the same money compared to before.
Sure but conversely some people might find it easier if social distancing has reduced their spending. Clearly a recession will impact overall spending but for those who can spend it could represent an opportunity.