look for rust under rear decklid,in spare tire area, door hinge posts, go to front of car look at front radiator support make sure its in 1 piece(they are very weak) strut tower to frame rail separation is a very common thing on L-bodies especially on hihg mileage cars or 1's that have been abused,Chrysler had a lot of electrical issues back in the 80's but if everything works on the car than all is good, the tranny shift rod linkage is a very sloppy design and the tranny is a very weak 1 it will self destruct at 200 ft lbs of torque instantly, i would average 1500 miles per tranny with that torque going easy on it, best thing to do is upgrade the tranny to a better stronger 1(many choices out there and cheap)
the cars were built to be quick and economical(not much of comfort) if you are over 6 ft go with the Omni,more headroom, the Charger has much better aerodynamics than the Omni, both have the same ride quality(lots of rattles especially if equippedd with factory aluminum louvers) they are alot of fun to drive, easy to work on and capable of running 12's for about 500.00 in mods,later.