Depends on the height of the curb, and the car, and the suspension's stiffness/dampers. That old '69 Camaro, the TransAm, rides curbs without issues. It's heavy and has a softer suspension, makes sense. The BMW we drove last week is lower, lighter, and has stiffer springs. Naturally, it gets easily unsettled by curbs, especially on that last corner at Brands. I did have a weird interaction with the outside curb through Dingle Dell, but that was because my front outside tire went off the curb, onto the grass, so it had a hard time gripping onto the curb, instead trying to throw me further off-track. The same happened with the Porsche at Oulton Park, after the exit out of T1. Outside tire goes beyond the curb, onto the grass, can't get grip on the curb because it's high, car wants to go off track. All seems pretty logical to me, unless there's something else I didn't notice?