Sam is not so lucky. He's used to a laid-back driving position he likens to lying in the bath with your feet on the taps, but here he's almost as tightly wedged as I - in control of a car that weighs 70kg-plus-passenger more than the single-seaters. Top speed is 50km/h lower, thanks to the extra weight.
But it's not all bad, he says. "The twitchiness of the shorter-wheelbase cars means you're driving on edge, but you can go fast in this without the nerviness, and the extra weight means you can get the power down earlier."
He says the car's balance remains unchanged, which is good news given I hope to survive this ride.
We're pushed from the garage, roll down pit lane then the downhill curve leading to Hampton Downs track and bang! My helmet whips backwards as Sam smacks the power on and we scream into the first corner, Bang! I head-butt the roll hoop in front, the tourniquet-tight harness all that's holding me in as we change to third, then second and scream through the next bends, cold tyres shimmying on a greasy track as we gun from 60 to 160 and back, down into the hairpin, accelerating hard through third, fourth, fifth to 200km/h then slamming into fourth, the digital tacho in front of me blurring through the revs as we haul round at 100 and on to the main straight accelerating to 220km/h, then BANG!
My head snaps forward as we brake for the turn, then back as we spear into the next short straight. Sam reckons he could close to four seconds from the single-seat cars but he'd need another lap or two. The car's computer shows 5-g of braking force and 2-g round corners - by God, it's fun.
But it's deadly serious for the best of our young racers who need the Toyota-run Series as a springboard to an international career.