I have the latest v8.0 on a July p90dl and just did a test. I had the autopilot set to 55 mph in a 50 mph zone. The speed limit changed to 40 mph and the car's speed dropped to 45 mph. When the speed limit went back up to 50 mph, the car's speed went back up to 55 mph, my previously set autopilot speed, not 50 mph.