Audi RS4 Avant versus BMW M3 Competition (G80). 0 points of retained value between them.
The RS4 Avant was never cheap at £61,625 new, but at £139 per horsepower it bought you something genuinely rare: a 443bhp estate car that could swallow a family holiday and still embarrass sports cars at a wet roundabout. At 243bhp per tonne it is no featherweight, but the all-wheel drive and composed chassis mean you access that performance almost all the time, not just when conditions are perfect. It is fast in the way a Swiss watch is precise — quietly, completely, without drama. The G80 M3 Competition is a harder car to ignore, and not just because of the grille. At 503bhp and 291bhp per tonne it is genuinely quicker, and the chassis is properly adjustable — rear-wheel drive when you want theatre, all-wheel drive when you want to get home. At £149 per horsepower new the premium over the RS4 was modest given the performance gap, and that gap is real on road, not just on paper. The better buy today is the M3 Competition. Both cars lack solid auction depreciation data, so neither can be declared a bargain on those grounds alone — but on straight value for what the money delivers, the M3 wins. More power, more driver engagement, a broader performance envelope, and a newer platform with more runway ahead of it. The RS4 is excellent, but it is the comfortable choice. The M3 is the correct one.