Since patch 1.40 hatchback sports' RPM will rev up and down when you get near 150KM/h. The RPM indicator ingame shoots up and down and the car sounds weird. The car also maxes out around the 150Km/h mark.

I have had some people complain about it in-game and some people are saying they work fine. I also left the game and went to the editor and placed a new hatchback sport, made sure it was not damaged at all, and drove it and it was still slow.

Update: This is not happening to every player. I have had some say it goes slow, and others say the car works fine.