In 2004 Rainer Zietlow founded his agency, CHALLENGE4 GmbH. CHALLENGE4 is a specialist in planning and executing worldwide automotive projects.
His automotive success includes three "Guinness World Records" and serveral long distance world records. In 2005 he established a new altitude record for series production vehicles with a Volkswagen Touareg V6 in Chile together with Ronald Bormann and a six-member team. He subsequently went on to complete the first natural gas-powered circumnavigation of the globe in a Volkswagen Caddy EcoFuel with a four-member team in 2006/2007. In 2013 he achieved the record with his eight-member team for driving the longest distance inside one single country (Russia) using several Volkswagen Amaroks. In between, Rainer Zietlow set two long-distance world records by navigating the famous road "Panamericana" from Tierra Del Fuego to Alaska in 2011 and, one year later, by driving the shortest time from Melbourne (Australia) to St. Petersburg (Russia).
In 2014 Rainer Zietlow and his team dealt with the 18,000 km long distance between the Nordkapp (Norway) and Cape Agulhas (South Africa). Due to an accident which forced the team to stay in Ethiopia for 13 days, they needed 21 days to complete the drive. Although this was a new record for this stretch, it was not the intended goal of Rainer Zietlow who wanted to complete the tour in just 10 days. One year later he tried it again, starting in South Africa, and reached Nordkapp 9 days and 4 hours later. In 2016 Rainer Zietlow and his two teammates set a new record from east to west across the Eurasian continent – from Magadan (Russia) to Lisbon (Portugal).
In 2017, Rainer Zietlow and his team even went on two record-breaking journeys. In 3 days 3 hours they drove from Dakar to Moscow. Four months later, they drove from Shanghai to Venice in 5 days 18 hours, crossing 11 countries including China, Kyrgyzstan, Uzbekistan, Turkmenistan and Iran. In 2018, a double tour followed: In 21 days, a Touareg prototype went from the VW plant in Bratislava, Slovakia, to the auto show in Beijing. The tour then returned to Wolfsburg in 24 days with two VW Touareg Type CRs. In 2019, another record followed on the American continent. On the Panamericana Highway, the journey went from Alaska to Argentina in 10 days and 19 hours.
In 2020, the beginning age of electric driving led to the longest distance within a country by EV to date: In a ID.3, Rainer Zietlow visited all of the approximately 830 VW dealers and nearly 650 fast-charging stations in Germany within 65 days.