The problem is there are so many factors coming into play:
The ban on Petrol and Diesel cars from 2030. The is means manufacturers will stop selling conventional powered cars totally by 2028 as they will not want to be the last man standing.
Covid has changed the way people commute. Fewer car and train journeys affecting the need for more new cars.
Prices and availability of Petrol and diesel filling stations. Little needs to be said about prices but the number of filling stations closing is on the rise and will be accelerated as people goto to Coffee shops to charge their EV and have a beverage / time out. Plus with less petrol stations it is going to be harder to refuel and at the mercy of supply and demand.
More legislation and rule changes. More motorways and dual carriageways have pollution control speed limits and here in Wales a blanket 20 mph speed limits in Urban areas and zero parking on pavements. Why have a big car if you can only trundle along at low speeds and then have difficulty parking it ? If you look at the scheme, most of the vehicles as 1.2l to 1.5l with very few 2.0 l plus.
Attempts to reduce the number of accidents, thefts and other negative behaviour will see the increased introduction of technology. For many years these were on the decline, now post covid they are increasing. Soon it will be mandatory for cars to have Emergency breaking, collision assist, dash cams, black boxes and speed control plus more autonomous driving.
Since our vehicles are funded through the public purse, the government could mandate no more fossil fuel cars on the scheme.
Plus if you were to buy a fossil fuel car now or next year and kept it for the average 3 to 5 years, will it have any value by 2028 ?
The rise of more smaller portable transport e.g. the current use of electric scooters and bikes. We could well see a rise in novel ways of transporting one or two people.
If anything, the next 3 years will see an even greater chip shortage as all the manufacturers build ever increasingly sophisticated cars.