The 1999 BMW M Roadster is a high-performance convertible based on the BMW Z3, featuring a 3.2-liter inline-six engine with 240 horsepower and a 5-speed manual transmission. It offers a sportier handling experience thanks to modifications like wider tracks, a lower ride height, and stiffer suspension components. The M Roadster is known for its distinctive styling, including M-specific wheels, side gills, and quad exhaust tips. 

Key Features:
Engine: 3.2-liter inline-six engine producing 240 horsepower.
Transmission: 5-speed manual transmission.
Suspension: Modified suspension with wider tracks, lower ride height, and stiffer components.
Styling: M-specific wheels, side gills, and quad exhaust tips.
Performance: 0-60 mph in approximately 5.2 seconds. 
Additional Details:
It features a limited-slip differential for enhanced traction. 
The M Roadster is a well-regarded sports car known for its balance of performance, handling, and style.