No; not those four Austalian lads in the colourful shirts (if you have young children you'll get that...The Big Red Car...?

) I have a problem with a passenger car conversion I am working on... it has a bad case of the wiggles....
The car is a Riverrosi coach I'm converting to another car, the bolster has been filed down for a better ride height, and the "lip" on the MT three axle truck has likewise been filed down to almost flat to reduce ride height. The car has FVM metal wheel that run true and well. The car "wiggles" around the track. Before I start adding weight ( and if I do, I'd add some tungston bar stock I have down in between the frame supports on the bottom of the car to get it as low as I can) I wondered if any of the local gentry ( read "a@@hats inc."

) have any thoughts on other solutions or things I can do to mitigate the 'wiggles".....?
Any help appreciated, as always.