I completely agree, I also run a 10 year old A6 Avant which serves me very well and doesn't owe me a penny. My allowance "rents" me some fun.
As a cash buyer, if you've got £30k to buy a new car, then as long as you're getting a good deal at a low APR, then it can make more sense keeping your capital elsewhere and "rent" the car.
If you're living off beans to scrape by "renting" a car, then you're an idiot.