Although not an actual maintenance device, this product warrants
consideration by virtue of its ability to enhance an 8-track
player's functionality. As the name suggests, this apparatus is
meant for the playback of plain old cassette tapes on an 8-track
machine, with car stereo consumers being the prime targets. Tests
at Plastikville show that the RoadRunner has great potential; for
those trackers who must supplement their 8-track listening with
the obviously inferior compact cassette format, this appliance is
for you. Slightly larger than an 8 cartridge, this adapter has a
slot designed to hold and drive a standard cassette. 
The signal from
the cassette is read on a standard tape head and then
electronically routed to the 8-track player's head. Although
there is a slight increase in "wow", the sound is
nearly as good as that of a standard 8-track -- very impressive!
With the RoadRunner, you can now charge down the autobahn and
listen to either cassettes or 8-tracks without ever sacrificing
any of 8-track's unique and wonderful audio properties!
Bob Schaeffer:
"An incredible engineering coup! Never has a cross-format adapter functioned with such panache. It actually enhances your 8-track machine's fidelity while playing cassettes! What finesse"!