Racing planes, demolishing speed records, de-slowing Captain Slow: over the years, Top Gear has done many ambitious and decidedly-not-rubbish things with the Bugatti Veyron. But none quite so ambitious as this.

This is the road trip to end all road trips: from Chicago to Los Angeles, 2400 miles along Route 66, in the car to end all cars. The Veyron Grand Sport Vitesse: the convertible version of the faster version of the fastest road car in history, the car we recently declared the greatest of the last two decades. If not ever.

You want numbers? 1200bhp of quad-turbo, W16 engine, over 1100 torques, four-wheel drive and a top speed of 260mph. Enough, it’s safe to say, to keep up with American traffic. Oh, and an asking price somewhere north of two million quid, which makes dicing with traffic in Chicago’s rush hour something of a puckering experience.

No one has ever done anything like this with a Veyron before. And they won’t again. With Veyron production ending next year before Bugatti opens a new chapter in its Going Faster history, this is it: the last, the ultimate Veyron road trip.

Which is why it had to be Route 66, the Illinois-to-California highway John Steinbeck christened ‘The Mother Road’. First finding fame in the 1930s as Dust Bowl escapees headed west in search of a better life in California, and again in the Fifties and Sixties as newly monied America developed a taste for the road trip, 66 remains perhaps the ultimate symbol of the freedom of the open road, of the way in which the car truly transformed the USA, and indeed the world.

Since bypassed by the freeways, 66 remains, at its best, a time capsule: a jumble of old motels, diners, neon and filling stations, a glimpse into a slice of American history time forgot, when the car truly was king. What better place to take the machine that redefined all notions of what a fast car could do?

Over the next week, we’ll be bringing you a daily photo-diary of our massive Trans-Am road trip, counting down to the sale of the ‘Adventures’ issue of Top Gear magazine – in print and electronically – where you’ll be able to read the full story (along with plenty more impressive car-based adventuring).

To get you in the mood, check out our shots of the first day. It started, as any Route 66 adventure really should, in windy Chicago…

Pictures: Justin Leighton