My SPX doesn't beep at all when you switch it on?
I think I might have found the problem. I did notice that there was a slight scratching sound when turning the wheels. So I've took it apart and it looks like one of the bearings could be knackers. I think the bar through the spur etc is slightly bent.
Here's some large photos which kind of show some indication of something not right. As you can see, it looks like the outer part of the bearing has also been turning inside it's holder, hence the black plastic everywhere.
Hopefully that's all it is. You wouldn't think the cars only been raced once!
http://www.web-development-server.com/DSC_0178.JPG
http://www.web-development-server.com/DSC_0179.JPG
http://www.web-development-server.com/DSC_0180.JPG