BMW revealed the Z4 M40i at the Pebble Beach Concours d'Elegance last month, but they weren't giving many details. Well, that's changed, and now we have a much better look at the car, including the sDrive30i that will arrive before that M40i shows up.

The long-awaited and much-teased roadster that will share engineering with the Toyota Supra will get here with a 2.0L turbo four. That sDrive30i model will use a new and more powerful version of BMW's TwinPower turbo engine that adds 15 hp and 35 lb-ft to give the Z4 255 hp and 295 lb-ft. That means a run to 100 km/h in 5.3 seconds.

The M40i also gets a big boost over that same engine in the other M40i cars. It's up 47 hp to make 382 hp and 369 lb-ft from the 3.0L turbocharged inline six. Both drive the rear wheels and use an eight-speed automatic gearbox with shift paddles.

The chassis uses a new double-joint front suspension and five-link rear. That's a first for BMW in a roadster and the company says that it offers improved ride and comfort. Extremely rigid front suspension components and subframes are said to improve handling and improve drivetrain acoustics.

The steering system has a standard variable power assist and a variable ratio. Changing the ratio and the assist is designed to improve stability in a straight line while giving better feedback and easier parking lot manoeuvring.

Adaptive M Sport suspension, M Sport brakes and an M Sport limited-slip differential are standard on the M40i version and optional on 30i. The M suspension gives a 10mm lower ride height with electronically controlled dampers that have three modes with increasing stiffness. The differential uses an electric motor to provide lockup and send torque equally to both wheels.

There are eight interior colours on offer for the Z4. That includes a Frozen Grey that's unique to the M sport models. There are SensaTec and Vernasca leathers as well as a special Alcantara, the latter again for M Sport models. You can even pick black or anthracite for the roof (though we're pretty sure that's the same colour), which can be electronically opened in 10 seconds at speeds up to 50 km/h.

The Z4 comes with sports seats standard, that have integral headrests. Those seats have 23 mm more travel than the last generation, to allow more seating options for passengers. The M Sports seats are optional and get electro-pneumatic backrests that can better hold you in place.

Storage space is up too, with a net-covered space between the seats, larger cupholders, and a 281L trunk that's 50 percent larger than the last Z4. There's even a trunk pass-through for longer items, though we're not quite sure how that works in this two-seater.

The new roadster gets BMW's Live Cockpit Professional that uses the latest version of iDrive and a pair of digital screens. One 12.3-inches for the instrument cluster and one 10.25-inch screen for the center stack. The system adds new haptic controls and a tablet-like touch interface for iDrive control. The system can also be updated over the air like a phone.

Active safety features offered include forward collision warning, daytime pedestrian detection, and lane departure warnings all standard. Radar cruise, blind spot detection, and rear collision protection with cross-traffic alert are optional. A new reversing assistant is offered that can handle semi-autonomous reversing when, as BMW says, "there is little margin for error or the driver does not have a clear view." It works by storing the steering motions you've just made moving forward and keeps the car on the same path backwards up to 50 metres. It's for when you've gone down a road that's a little too narrow, not for parking.

The 2019 Z4 sDrive30i is set to arrive at Canadian dealers in March, with pricing to follow. The M40i will follow later next year as a 2020 model.