Complex sentence: The R18 station wagon was also sold in the North American market from 1981 to 1986, and the sedan in 1981-1982; it failed to even come close to living up to previous AMC products' reputation for reliability, and was not a success.
Split into simpler sentences: The R18 station wagon was also sold in the North American market from 1981 to 1986, and the sedan in 1981-1982. However, it failed to even come close to living up to previous AMC products' reputation for reliability, and was not a success.