[autoavia]

You need to remember that mass produced slotcars are made on a production line where each operative has a set amount of time to complete their part of the assembly process. If something doesn't go quite right they have to move each car on down the line even if they haven't got the assembly perfect and if it is really bad it should get pulled on quality inspection.

 The problem with the GTO could well be something simple like the factory fitting a stronger magnet than Fly specified because they ran out of the correct strength. Don't forget many factory workers wouldn't understand the difference the substitute magnet would make to the way the car runs so they have just found a way to get the product out on time and avoided holding up production of the next item due for assembly. In the manufacturing world time is money.    
 I remember SCX 4 wheel drive rally cars 20 years ago that had exactly the same problem.
 
 I never expect to take a car out the box and find it runs perfectly. Some may run ok but there are always little bits and pieces which can be done to improve them. I race on a wood track with copper tape so no magnetic effect which shows up every little fault. Magnets hide a lot of problems. For instance Ninco cars, amongst others, never run well on wood straight out the box because the tyres and even the wheels just aren't true so they hop all over the place but they are fine if you run with magnets as the downforce from the magnets hides the problem.