A more powerful standard engine and revised styling constituted 2006 updates of note to Volkswagen's uniquely retro-styled automobile. As before, New Beetles came as two-door hatchbacks or convertibles. Headlamps, taillamps, fascias, and side sills were reworked. A 150-horsepower 2.5-liter five cylinder was now the standard engine. The 115-horsepower 2.0-liter and 150-hp turbocharged 1.8-liter were dropped. Available only as a hatchback was the TDI model, with a 100-horsepower 1.9-liter turbodiesel. A five-speed manual transmission was standard. Six-speed automatic with a manual shift gate was optional. Every New Beetle included antilock four-wheel disc brakes and front side airbags, with head and torso protection. An antiskid system and traction control were standard. Standard wheels were 16-inch size; 17s were optional. Audio systems had a jack for connecting digital music players, and satellite radio was available for all models. Also optional were leather upholstery and heated front seats. Larger cupholders went into the redesigned console. Convertibles had a manual-folding fabric top or optional power top, and included a heated glass rear window. Rollover bars deployed if sensors detected an imminent tipover. OnStar assistance was no longer available. Although New Beetles roughly competed against the Acura RSX, Mini Cooper, and Scion tC, they had a retro-look all their own, descended from the original Beetles that took America by storm in the 1950s and '60s.