One more aspect of N gauge that is going to drive me crazy. Micro-Trains, Katy, Rapido, ect..... How many different brands are there? And it seems like each brand has at least a couple different styles. (regular long short.... etc) (Well that holds true it seems except for Rapido one coupler all the time.) I think it was Micro-Trains that actually had a chart for all it's different couplers. (Although it made about as much sense as NMRA standards to me.) Are there any that retrofit to most cars without hacking them up, filing them down or making shims so they are at the correct hight? And what about the eingines? On my Bachmann, the couplers are attached to the trucks. Does this mean I have to change out the whole truck if I want to change couplers?