Don't get too hung up on the £40k thing. The first years VED is included in the OTR prices, and years 2-5, whilst seem like a lot of money to pay out, only equate to a trip to Starbucks each week. And let's face it, none of us will be doing as much of that for a good while.
I've never been to a Starbucks, and at their prices I'm not likely to.

If I'm going to pay £4 for a drink its going to be justifiable because it's a pint of beer with tax paid on it.

My A4 falls in the luxury bracket. It is an unfair tax to be paying out for 5 years on the basis that in year 1 it was briefly worth more than £40k.
They should load it all at the front end in the OTR price (oh wait they already do a bit of that too!).
Some very ordinary cars are breaching that limit because
1. RRPs of cars are currently ridiculous vs what you can aim to pay.
2. The Government hasn't increased the threshold in line with inflation, so more cars are being caught up in it.
No escaping it though.