 The IS convertible features a three-piece aluminum hardtop that can retract in 21 seconds, a roof-brake mechanism slows panels as they close and near the windshield.The IS 250 C and IS 350 C are offered with a six-speed automatic, while the IS 250 C was offered a manual transmission and all-wheel-drive version.However, as of 2015, the IS C is only available as rear-wheel-drive.