Hi Guys, I'm new to N scale and am trying to get used to these darned Rapido couplers.  Many of my cars do not couple correctly because they are at different heights, either too high or too low, sometimes they just barely couple and will uncouple when I run the train, or won't couple at all because of not matching up height wise.  I don't see an easy way (if any way at all) of either raising or lowering the couplers as they are body mounted.  The only thing I can think of is to heat the plastic shank somehow and bend it to the correct height but I'm not sure if that makes sense or not.  I spend a lot of time recoupling various cars and that is taking the fun out of running my trains and gets to be tedious after a while.  All my cars and engines are Bachmann and everything is fine other than this coupling problem.  Any suggestions?