Hi, just got my first 2 Carrera cars and having some difficulty running them consistently on my Scalex Sport track. I've heard one solution is to file the guide down on the Carrera cars as they're a but deeper than Scalex cars. Is this the case? Also I'm using the standard Power & Control with only one transformer (yes I know I should get two!). I'm presume going to a second transformer (1 per lane) would also help.