High-profile recruit Edoardo Mortara says he was encouraged by his first taste of Mercedes' DTM package.
Having finished second in the 2016 championship with Audi, Mortara will join Mercedes next season.
The Italian got an early chance to test with his new outfit at Jerez last week, alongside the traditional young-driver running.
While Mortara was limited to 45 laps across the four days, he said it was a positive start.
"My first impressions were good," he said.
"Of course, this is a completely new field of endeavour for me, but still, I was very pleased to be able to post my first few laps in the Mercedes-AMG C 63 DTM before the end of the year. I would like to thank Mercedes-AMG and Audi Sport for that.
"I immediately felt at home in the team and was aware that they were doing everything they could to make me feel at ease, which was very nice of them.
"I was able to gain some first impressions despite not being able to post all that many laps over the four days.
"It's always good to get in a car and drive. I'm now looking forward to my first test in the new year."
DTM testing will resume in February, ahead of the introduction of the series' brand-new cars.
All three manufacturers will cut back from eight cars to six, and Mercedes is yet to outline which three of its 2016 drivers will make way to account for the reduction and accommodate Mortata.
It did, though, have Gary Paffett and Robert Wickens testing its hybrid 2017 machine at Jerez, while Formula 3 driver Maximilian Gunther and ex-DTM racer Maro Engel were its designated young drivers.
"The final test week of the year was highly satisfactory from our point of view," Mercedes DTM boss Ulrich Fritz said.
"We once again managed to put in a decent number of test kilometres with our development vehicle and to record plenty of data.
"We are delighted that Edoardo was able to complete his first ever stint in a Mercedes-AMG C 63 DTM this week.
"He has set a good standard for our two [young driver test] guys."
Audi tested World Endurance Championship LMP1 refugee Loic Duval in its DTM car during the week, with Formula Renault 3.5 and GP3 race winner Nyck de Vries and GT racers Kelvin van der Linde and Dion von Moltke.
BMW ran juniors Ricky Collard and Joel Eriksson, and IMSA factory GT driver John Edwards.