Its your front suspension. Especially the lower control arm "thrust arm" bushing. It absorbs the rearward motions to the front wheel. It absorbs alot of energy. The OEM has a liquid filling, for a nice luxury car noise/vibration/harshness ride. But it gets beaten up, cracks, and loosens up.The shop Said the rubber on my thrust arms are shot. Also said my ball joints and struts are wiped out. I’m waiting for a parts list and I’m going to start with the front end first and then save up and do the rear. I’ll have them check the rotors too. I’m not really driving the car too much until it’s taken care of
I definitely get more vibration on hot rotors and I’ve always had that sudden jolt in the steering wheel if I stab the brakes. For what it’s worth it’s a great car that I’ve made great progress with since I’ve purchased it. I’d love to re do the whole suspension and get the driving experience it was designed for.