Testing Doohan's Mercedes-Benz SL63 AMG

But we've beaten him to the prize - a sinister gunmetal grey Benz belter. The SL63 AMG is idling with intent as I arrive in the pit lane that will be the home of Formula One this weekend as the 2013 grand prix season kicks into gear.

The final touches are being applied to the course but the SL has already been polished and preened for an early preview of the action. It is strong and eager as I ease onto the main straight and - very, very briefly - uncork its turbocharged V8 power.

There is a strict 40km/h speed limit for me, but Doohan will be let completely off the leash when he compete in the Ultimate Speed Comparison this weekend. He is up against his racing mates David Coulthard and Casey Stoner in a contest that's intended to highlight the difference between a regular road car, a V8 Supercar and a full-on F1 car.

Stoner is wheeling the V8 this time and Coulthard, a grand prix winner in Australia with McLaren, is sliding into one of last year's Red Bull rockets. "It's a bit of fun," Doohan tells me. "You're never going to beat a Formula One car, even in an AMG Mercedes."

I know exactly what he means because I had two years as the road-car rabbit at Albert Park, running BMW M cars against the grand prix greyhounds. I will never forget the first time that Christian Klien blasted his BMW F1 car past me down the front straight, running more than 100km/h quicker in an explosion of noise and violence.

I had always though that an M car was fast, but as I applied the brakes for Turn One at around 210km/h he calmly shifted into top gear and zipped in ahead of me trailing a huge wash of dirt and debris from the unused side of the track. It took me a while to get my breath after that one.

This time, I know the SL63 and I know Albert Park, and I know the enjoyment that Doohan will be having. He might have won his five world titles on two wheels, but the 500cc tyro loves fast cars and has been an AMG ambassador for more than 10 years.

What's he like as a driver? He's fast for sure, as I have seen from the passenger seat, but he's never going to score maximum style points. "The SL63 is a fantastic car.To romp it around the racetrack should be a bit of fun," Doohan says.

"It's not too serious, but it is still a race. I know Mercedes-Benz wants to win, and so does Red Bull Racing, and Casey. The idea is to have all three cars cross the finish line at exactly the same time. "But you don't want to put the car in the wall."

This car is specially built for Doohan's drive, and weighs in with a $409,575 pricetag. When you catch your breath, that means a base price of $381,500 boosted by metallic grey paint that looks like it was peeled off a jet fighter, an AMG performance package that unleashes extra turbo torque, a panoramic sunroof and matt-black alloys that are 19 inches on the nose and 20 inches on the tail.

But the most striking difference is Doohan's name on the side windows. And that's what has people staring as Carsguide noses out into ordinary Melbourne traffic in the F1 racer.

I have driven the SL63 before, and absolutely loved an early-morning blast last year in southern Spain, but its a revelation on the pockmarked bitumen. It is obviously fast and firm, but also surprisingly cosseting and enjoyable. And even the seven-speed auto can slur for minimal intrusion.

For me, it's a better everyday car than the Benz SLS, because it rides smoother and you can also drop the top for sunshine fun. It has more than enough performance with 395 kiloWatts and 800 Newton-metres, even though the SLS is more brutal again with 420kW, and you save big against a gullwing that is priced from at least $468,320.

As we head around Albert Park and dodge the workers who are putting the final touches to the course, Doohan's words come back to me. "The only time things get a bit iffy in a road car is if the track is wet. Then you're working," he tells me.

This is a bit of a surprise from a bloke who had so much brilliance on a bike. He might have ended his career in an ambulance, but Mighty Mick always rode like he was racing with the devil on his tail. And, even today, he does not play well with others.

He has channeled his efforts into a booming aircraft business in jet charters, owns nightclubs and property, and has a matt-black helicopter parked in the shed at his Gold Coast spread.
When he pulls on his famous helmet this weekend, he says he is looking to have some fun and a bit of a speed.

"You can't just stooge or dawdle around. I remember the time that Pedro de la Rosa disappeared under the rear wing of Jaffa, that CLK63 Black Series, as we were coming onto the straight. I just didn't see him," Doohan says.

"But my job is to be consistent every day. We want to show people the difference in speed between the three types of cars. "It should be good with DC and Casey. We'll be looking across at each other and having a bit of a laugh."

This reporter is on Twitter: @paulwardgover