There were several obvious differences between the RR and GTX. The GTX and the Sport Satellite shared the same grille and Tail lights. The RR grill was different that the base Satellite in that it had a dark argent paint and satin black finish. The Satellite had a silver finish overall. The GTX also as noted in the other responses had wheel housing trim, fender mounted turn signal indicators, wood grain on the dash and a wood rim blow steering wheel. The door panels also were different than the RR. In 69', the RR came with additional options that the 68 did not. Front disc, Décor interior pkg. a tape pin strip instead of the painted one. The Magnum 500/ Road wheel was also an option. These were 14" only wheels. The only way you could get a 15" wheel was to order a hemi or 440/6pk in the RR. These were steel wheels with acorn lug nuts without wheel covers or poverty caps. 69' also offered the N96 Air Grabber pkg. Other than these special order options, the RR was as described in the earlier response, a bare bones high performance car! I hope this helps clear up any questions you have on the B bodies in 68/69. It is a Mopar or NO CAR!

The Road Runner and the GTX were both B-body vehicles based on the Satellite as was the Bellvadere. The other difference besides those mentioned in the other persons answer was that the GTX cost a little more and had more trim such as around the wheel wells and had the blinker indicators on the front fenders. The Road Runner which came out in 1968 was built as a return to the lowest price lower option vehicle where most of the money was put into the drivetrain and the performance without the extra frills which had crept their way into the muscle car market on most other vehicles by that time. Even a carpet was an option if you did not want the floor covered in the same material as the trunk mat and most were bench seats too. Of course the beep beep horn and Road Runner emblems were also a difference. As a side note, Chrysler paid $50,000 to Warner Brothers in 1968 for the rights to use the Road Runner image and name.