The Pontiac Bonneville is a full-size automobile which was built by the Pontiac division of General Motors from 1957 to 2005. It was introduced as a limited production performance convertible during the 1957 model year. For the last year of production, Pontiac gave the mid-level SLE the new GXP styling. The 2005 SLE featured all GXP styling cues, except the wheels, badging, muffler tips and engine all remained unique to the GXP. Keyless remote central locking systems are available for most Pontiac Bonneville trim levels and are standard features on all newer models.