Wolfsburg have confirmed the signing of Stoke City forward Tuncay, who becomes the German club's fifth signing of transfer deadline day.
Tuncay joins Steve McClaren's side after making just 18 Premier League starts for Stoke since joining the club from Middlesbrough in the summer of 2009.
The Turkey international has signed a contract that ties him to the Bundesliga side until June 2014.
Tony Pulis said: "Tunny came to me at the weekend and asked me if the club would help him to achieve his dream. He has always wanted to play in Germany and missed out on several occasions in the past.
"So this is a fantastic opportunity for him, and it is a fantastic deal for the club when you consider what we paid for him when he signed from Middlesbrough. I spoke to Tunny a number of times about his hopes and ambitions in his playing career and it was quite apparent that he saw Germany as a great opportunity not only to be much closer to home but also to boost his international prospects as well."
Wolfsburg have also signed Bayer Leverkusen striker Patrick Helmes for a reported €8 million, with the striker arriving as a replacement for Edin Dzeko following his £27 million move to Manchester City.
Anderlecht midfielder Jan Polak was the third signing announced by Wolfsburg on Monday afternoon, and he makes the move to Germany on a contract until 2013.
Wolfsburg had already announced that they had signed South Korea international Koo Ja-Cheol and Venezuela's Yohandry Orozco on a busy transfer deadline day.
"As well as experienced players, who will hopefully help us in the present, we have also brought in players with potential," Wolfsburg sporting director Dieter Hoeness told the club website. "This is because our medium-term goal remains rebuilding a new team, which is characterised by a will to win, quality and passion."