55 Chrysler 300

The Chrysler 300 "letter series" were high-performance luxury cars built in very limited numbers by the Chrysler Corporation in the U.S. from 1955–1965. Each year's model used a new letter of the alphabet as a suffix (skipping "i"), reaching 300L by 1965, after which the model was dropped.
The 300 "letter series" cars were among the vehicles that focused on performance built by domestic U.S. manufacturers after World War II, and thus can be considered one of the muscle car's ancestors, though much more expensive and exclusive.
Chrysler has recently started using these designations again for sporting high performance-luxury sedans, using 300M from 1999, and continuing the 300 series with a new V8-powered 300C, the top model of a relaunched Chrysler 300 line, a new rear-wheel drive car launched in 2004 for the 2005 model year. Unlike the first series, the second does not have 300 hp (220 kW) engines, except for Chrysler's current top-line 300C models.

http://en.wikipedia.org/wiki/Chrysler_300_letter_series