Did a simple replacement for the failing aftermarket parking-sensors in the Mercedes-Benz E-Class 200E W124. Pretty simple task. Luckily the hole size matched out sensors so it was a direct replacement without needing any more work. Removing the bumper was not hard, but unclipping the trim on the bumper took a bit of work.
Parking Sensors – https://www.fasmoto.com/safety-security/driver-assist