There is a scurry of activity as a new motorhome picks its way through the cars, bikes and scooters that litter the Spa paddock. Then it stops beside me and Guy Smith leans out of the driver's window to proffer a hand. It is an unlikely entrance for a Le Mans-winning racing driver, but then this is no ordinary event. Smith isn't here to race an Bentley Speed Eight, he's here to join our bid for glory in the world's longest motor race, the 25 Heures VW Fun Cup a Francochamps.
The huge Breitling is instantly familiar and so are the personalized clothes. He looks every inch a professional racer, which is in sharp contrast to yours truly and the third member of Top Gear Team Uniroyal, club racer Fergus Campbell. "Ferg" and I have both raced and won before, but we fall into the drawer marked "competent" rather than "inspired." Neither of us ever thought we'd end up teamed with a bloke who matched Juan Pablo Montoya's pace in junior formulae and now races beside a guy called Johnny Herbert.
We park the motorhome and make our way into the McLaren Mercedes pit, where our chariot awaits. The VW Fun Cup cars are designed to look like original Beetles, but only the windscreen is shared with Hitler's favorite. Bespoke, GRP panels hide a tubular steel chassis that's built by Dubois Racing in Belgium. The mid-mounted, 1.8-liter engine is sourced from VW and mated to a five-speed transmission that's normally found in an Audi A4. They're used in national series across Europe and are designed to provide fun, safe and cost-effective racing.
Subtle mechanical tweaks, including the introduction of carburetors, increase the power to 130 bhp, but with a curbweight of 1,676 lb and brick wall aerodynamics, the Beetle's could never be described as rapid. They're certainly a far cry from the 610-bhp, 1,984-lb Audi R8 that Smith drove at Le Mans just a few weeks ago. Coincidentally, our race number is 88, the same as his Audi's.
They might not be quick, but we should at least enjoy some close and frenetic racing. At 4 p.m. on Saturday, 130 identical cars will leave the starting grid and, all being well, they'll still be dicing come 5 p.m. on Sunday. It sounds terribly daunting and my nervousness is compounded by the news that half the drivers in the field are filled with Latin blood.
Practice will start soon, so we return to the motorhome to change into our new race suits, which are a "tasteful" shade of yellow. "It's best to remove your underwear," says Smith, alarmingly. "Your boxer shorts aren't fireproof so if the car catches fire, they tend to stick." Commando it is then.
He's also encouraging us to drinks gallons of water in the build up to the race. "You need to hydrate yourself," he explains. "You should be going to the toilet all the time and it's not until you're peeing clear water that you know you're properly hydrated. It stops you getting cramps during the race."
It sounds sensible but what happens if I need the toilet during a race stint? "You don't want to crash with a full bladder because it can explode," says Smith. "If you need to go, just pee in the car. Johnny [Herbert] does it all the time." Suddenly Le Mans sounds a lot less glamorous.
Testing starts at 3 p.m. and it's the first time that any of us will have driven our race car. You sit centrally in the Beetle, ensconced in a rollcage and confronted by a black slab of a dashboard. A centrally mounted rev counter is joined by a plethora of secondary gauges and an array of toggle switches that control everything from the headlamps to the (pathetic) windscreen wipers. The cockpit is surprisingly roomy but the letterbox windscreen offers a restricted view. These cars are not for the claustrophobic.
And Spa is certainly not for the faint-hearted. It's shorter than it once was but at 4.3 miles, it's still one of Europe's longest circuits and home to one of the world's most challenging corners. Eau Rouge is a daunting inverted "S" that plunges down then up hill, while posing the question: "Are you sure you want to be a race driver?"
I've been told that it's taken flat out in the dry, but it takes me a few laps to build up some confidence. The Beetle uses conventional road tires and they take a while to come up to temperature. Even then, the car moves around a fair bit and the unassisted steering loads up considerably during hard cornering. It's clear that exacting the most from it will not be easy.
At the end of the session, we debrief. While Fergus and I can describe the car's behavior, Guy already has a game plan for going quickly. "You need to let it take a set," he explains. "You brake, turn in and then wait for it to roll and for the outside rear wheel to take up the load. Then you can get on the power. It's a bit like driving a low-powered kart. You need to be really smooth with the inputs and not lose any momentum.
"It might sound absurd but in some ways it's harder to drive than the Bentley or the Audi. On those cars everything works exceptionally well and they'll do exactly what you want. I'm not saying they're easy to drive, but the Beetle represents a different kind of challenge. I can't remember the last time that I had to heel-and-toe a downchange."
It's a fascinating insight born of experience, talent and keen intelligence. Anyone who thinks that modern racers are brainless dunderheads is wide of the mark. Smith started driving a kart at the age of 5 and was runner-up in the World Championship before progressing to cars. He's been a de facto professional for more than 20 years and it's reflected in everything he does. Slick in front of the TV cameras, charming to the sponsors and instantly rapid in the car, he's the epitome of a contemporary pro.