You need a Hellcat to get to 200 MPH. The Demon has more HP, but I've read conflicting reports on the top end speed. I drove a ~500 HP Challenger on the Autobahn a few years ago Top speed was listed at 186. After getting use to it, 120 MPH seemed a nice comfortable speed. I hit 155 - 160 and it was pretty much white knuckle in the Challenger. Tire noise and air invading the passenger compartment raises stress levels. 120 in a high end MB is cruising speed on the Autobahn.
I once hit 120 in my old Honda Accord V6 going to Utah from Las Vegas. I didn’t keep it there long. Just wanted to see if I could hit it. I brought it back down to cruising speed of 100. The speedometer went to 160. I think the speed limit was 80.