They would have to quit their jobs to undertake the trip which brought with it the problem of money, or lack of it.

Inspired by a shared interest in "the rise of China and Chinese brands", Bikker and Striker came up with a clever, ambitious scheme to fund their travels - they would seek sponsorship from mainland companies, figuring their idea to use only Chinese products during the entire journey would be excellent publicity for home-grown brands.

"We wanted to do something extraordinary, an adventure," says Striker, an urban planner. "We didn't want to be two hippies on the road, so we turned a dream into a plan. And we wanted to share with the world the China that we see every day around us. A China that is cool, innovative and that can also make quality products."

They sketched out a route that would take them through long stretches of the old Silk Road that Marco Polo travelled, through Kazakhstan, Uzbekistan, Turkmenistan, Iran, then Turkey and the rest of Europe to their home country - about 20,000 kilometres in all - and took the plan to various Chinese companies.

Having worked in digital advertising and branding, Bikker was only too aware of the image problem faced by Chinese products. But he was keen to tap into what he figured would be a changing tide - at the time, home-grown successes such as Huawei were already better perceived in Central Asia than in their home markets, but phone maker Xiaomi was still relatively unknown outside China.

"Surprisingly, the Chinese were even more enthusiastic when we talked about the project because they have this double feeling, a sensitive nerve about their own brands," says Bikker. "The companies were all very interested, but struggled with whether they should advertise, or hide their heritage, or pretend to be foreign [a common practice in many industries]."

BYD Company, a manufacturer of rechargeable batteries and petrol and electric vehicles, came in as the main sponsor, providing travel expenses and car (a model using petrol since charging points were non-existent in the steppes). Before long, major names including Huawei and Lenovo signed up to supply them with mobile phones and laptops.

Bikker and Striker eventually set out from Shanghai at the end of July last year with some fanfare, given a cheery send-off by friends and sponsors, which kitted them out with a Chinese camera (AEE), tent and other outdoor gear (Ozark), clothing (Xiyouji) and even sunglasses (Braos).

"It was a constant adrenaline rush, living on a high and I tried to take in as much as I could," Striker says of their three-month journey. "Even during the challenging moments of falling off a horse and being injured or three days of red tape at the Turkmenistan-Iran border, there were no lows for me."

A third of their route lay within Chinese territory, as they drove from Shanghai to Urumqi and on to the Kazakhstan border. Along the way, they passed through massive urban sprawls as well as more untouched areas such as the beautiful desert lands beyond Urumqi, with their friendly people.

One of Bikker's favourite moments was when they left their car to go on a long horse trek over Sichuan grasslands to visit some nomadic tribes.

"The only way to reach their settlement is by horse as there is a river to cross; they are truly nomadic, living in camps off the grid without electricity," he says.

Unfortunately, that was when Striker bruised his ribs falling off his horse. The duo went on a frantic search for the closest doctor but found he didn't have an X-ray machine, so they had to endure a 10-hour drive to the nearest hospital with the equipment.

"I was in a lot of pain and it took three weeks to recover; it was an interesting experience" Striker recalls. "But it was great having a friend like Rogier along who was such great help."

They were constantly asked about the number of breakdowns they had, typically followed by jokes about their Chinese-made car. In Germany, many people were sceptical about the enormous distances covered in their sedan. But apart from an accident in Uzbekistan ("entirely my fault," Bikker quips of the collision that left a taxi totalled while they merely suffered superficial dents), their BYD F5 withstood the gruelling journey without any problems.

"That's the true answer and I'm not getting paid to say this," Bikker adds. "I didn't have to open the hood once, which is good since I have no idea about cars."

Striker confesses they were not entirely sure about some sponsors' products because they had not used them before the trip.

"But that was part of the adventure," he says. As they finally rolled into Rotterdam on October 31, "it showed the endurance of the products, especially the BYD car, to combat some of the highest mountains and hottest places in the world".

That's not to say the two friends had a smooth ride all the way. Besides Striker's horse-riding accident and their collision with a taxi, Bikker had his bag and passport stolen in a Kazakhstan bar (fortunately, the owner was able to retrieve it quickly for him).

They had many beautiful experiences, especially when they decided to set aside their caution and suspicions in Iran, Bikker says.

"It was the best thing we did, saying yes to almost everything. It was amazing seeing their daily lives and stay in people's houses ... There's so much media bias about the dangers of [Iran] but these people were the friendliest."

Turkey was the first place where Bikker and Striker began bumping into big crowds of Chinese tourists, and they drove around trying to catch the attention of mainland tour group crowds with their Chinese car and plates.

Once they reached continental Europe, it was an easy drive home; "the last month was just a holiday," Bikker says.

Memorable experiences aside, their expedition has also proved to be a big career booster for the two friends.

It's been most remarkable for Bikker, who took on a new job this month as chief executive of Shanghai-based branding agency Tomorrow.

The company used to focus on introducing Scandinavian companies to China, but has now made a complete turnaround to help Chinese companies build global awareness of their brands instead.

"The company was inspired by Brand New China; they always thought they had to do something different but until then didn't know what," Bikker says.

Chinese companies increasingly want to establish their own brands, rather than just serve as manufacturers for Western brands which squeeze them with ever smaller margins. "But this takes expertise and training and understanding. It doesn't happen overnight. It's the next step for China," he says.

For his part, Striker published a book this year titled about urbanisation and global changes based on insights gained on their journey.

"It's a cliché but the world is big. And our human footprint is large as well," he says. "Although cities take up only 2 per cent of the global landmass - the influence of construction, food production and resource extraction can be seen almost throughout our entire journey."

Last month he moved to London to work for planning and engineering consultancy Arcadis, as a global consulting lead on building strategies to improve quality of life.

Although he has left the country, Striker says: "China shaped me for life."