The Spitfire was an inexpensive small sports car and as such received rather basic trim by today's standards, including rubber mats and a large plastic steering wheel. It was nonetheless considered fairly comfortable at the time, as it had roll-down windows and exterior door locks, as well as relatively full instrumentation. These early cars were referred to both as "Triumph Spitfire Mark Is" and "Spitfire 4s", different from the later Spitfire Mark IV. The "Spitfire 4" name indicated the possibility of the appearance of a six-cylinder version.