Neon tubes
Neon lamp tubes were introduced into widespread production for the CHMSL on the 1995 Ford Explorer, and notable later uses included the 1998 Lincoln Mark VIII, with a neon tube spanning the width of the trunk decklid, and the BMW Z8, which made extensive use of neon. Numerous concept cars have included neon lamp features, from such manufacturers as Volvo. Hella offered an aftermarket neon CHMSL in the late 1990s.
The linear packaging of the neon light source lends itself to the linear packaging favored for many CHMSL installations, and neon lights offer the same nearly-instant rise time benefit as LEDs. However, neon tubes require an expensive and relatively power-hungry ballast (power supply unit), and as a result, neon lights have not found significant long-term popularity as sources of light for automotive signaling.