IN THIS FEATURE The uncompromised Z car Confidence in the car A remarkably practical car

Back at Estoril, BMW's confidence in the car was revealed at the driver briefing. No fingers were wagged and no limits were imposed. They just asked, very politely, if we wouldn't mind terribly not crashing their cars, handed us the keys and pointed us down the pit lane straight. They didn't even mind when we started to race, which is usually when the red (and black) flags come out at these events.

Lap one was a warm-up, waving another driver past whose trousers were, apparently, on fire. By lap three, using all of the engine's 8,000rpm, the car had begun to reveal that hardcore soul. Through a 100mph kink leading to a long downhill straight, the Z is unbelievably planted, shrugging off a slight camber change and charging down to a hard left, with maximum braking from about 125mph. Ten laps later, the brakes are noisy and graunching but there's barely any fade and I still have enough confidence in the M to brake very late.

Through the slower corners, the back end of the car feels particularly alive, moving around and telegraphing the sort of messages you really need in order to keep the rhythm going (and the grass out of your brakes). Carry too much speed and the nose washes wide with understeer, but this is something you can remedy by switching off the DSC stability control. Then you've got yourself a throttle-adjustable hoon machine. And pressing the Sport button gives even sharper thottle response.

It takes seven kinds of stupid to put this car off the track

The feel and feedback from the steering is also fine, its accuracy allowing you to place the car with pretty much millimetric precision. But didn't the Z4 M toss two journos into the tyre wall at Estoril? Well yes, but in its defence, you'd have to be seven kinds of stupid to provoke such a reaction. After a day spent with the Z4 at and beyond the limit, I concluded they must have accidentally pulled the handbrake or some such.