From 2003 to 2005, his work included overseeing the interior and exterior design/redesign of the S-Class, M-Class MKII (W164), SL, SLK MKII (R171), SLR McLaren, Maybach Mercedes, and the Grand Sports Tourer concept car and its subsequent production version.

Following his tenure with Volvo, Mattin began teaching at Umeå University in Sweden.

[3] In 2011, Mattin began working as the chief designer of AvtoVAZ's Lada, a subsidiary of the Renault-Nissan Alliance.

[3] In August 2012 during the Moscow International Automobile Salon AvtoVAZ presented the new SUV Lada XRAY designed by Mattin.

[5] Mattin introduced the updated logo of "AvtoVAZ" at the "Auto World" international exhibition in St. Petersburg on 1 April 2015.