The Berlin-based company is benefiting from the increasing digitalisation in the used car trade with its platform "wirkaufendeinauto.de" and also its focus on growth in sales to private customers through its Autohero unit.
"Thanks to our reconditioning sites, we should be able to prepare vehicles for resale faster and more efficiently to meet the huge demand," Chief Executive Christian Bertermann told Reuters in an interview.
Auto1 said it now expects its 2021 revenues to come in at 4.5 billion-4.6 billion euros ($5.09 billion-$5.20 billion) compared with its previous guidance range of 4.0 billion to 4.4 billion euros.
Auto1's full-year gross profit should reach 415 million to 425 million euros compared with the previous target of 380-410 million euros, the company said.
"Our higher outlook also reflects that we are selling more higher-value cars, which is directly attributable to the success of Autohero," finance chief Markus Boser said.
Shares in Auto1 were up 5.5% by 0945 GMT.
The company said its third-quarter revenue rose 64% to 1.26 billion euros, the company's highest quarterly sales since its stock exchange listing in February.
($1 = 0.8842 euros)
(Reporting by Nadine Schimroszik. Writing by Zuzanna Szymanska. Editing by Jane Merriman)