The did a in depth review of basically every car maker in Europe after that. For a while BMW was the only German one that seemed to come out almost clean. until they didn't. Peugeot and Renault were fined in France. As was Fiat in Italy if I remember well. The German OEMs were the worst, with VW leading the pack and Mercedes being a distant second. VW did something clearly illegal, most others thaugjt the just skirted the edge of legality. Maybe that skirting would have worked if it wasn't for public pressure after VW was found of having crossed line of skirting deep into cheating territory.

VW wasn't the only having tweaked emissions, VW was the only one having clearly cheated. that's why they are remembered for it.