We can't come out and say "premium German-branded cars park worse". All we can say is "premium German-branded cars appear a lot in our database", but that's a self-selected dataset and not defensible. What we really need is access to a (suitably anonymised) dataset from Parking Services, say a week's worth of issued ticket data, with all the number plates replaced with random numbers and some other tweaks to prevent de-anonymizing, but with car make/model retained. We'd also need to know the percentage of these brands in use in the city compared to other models, to see if there was a significant variation. Then we'd know.
And, being city-wide, it would stop us being picking on particular schools. Like Christchurch School, Clifton, that appears to have a serious parking problem. The problem being: not enough space for everyone driving in. And seemingly everyone who does drop their kid off there uses Ein Auto aus Deutschland.
X21SJC may actually be a resident's car parked on the school-keep-clear zone, so denying parents their rightful place.
The parents are forced to park round the corner, the red BMW H674HJO narrowly avoiding being scraped by a small child having the audacity to cycle to school with a parent -neither of them wearing a helmet. We are shocked and appalled by the risks these people are taking.
Further along, another Mercedes R116KTC.
At least the disabled parking area is left alone.
Some of these cars could belong to residents. We'd need to audit the street on a Sunday morning to build up a better model of who is parking where round these narrow streets -streets that voted against becoming residents parking, incidentally. Presumably because it was obvious to all that an RPZ would take the pavements on these roads out of play, which would be unacceptable.