Arden, the German tuning firm that's been tweaking Jaguars for decades, is teasing us with this concept shot of its new Jaguar XF AJ 21. We just drove the 2009 Jaguar XF and felt the sheetmetal was lacking some excitement. In a good manner, it appears that Adren has addressed some of our concerns with its aerodynamic sport package including new front and rear bumpers, new side skirts, and a more aggressive wheel package. Look closely and you'll notice the cat is back on the hood (maybe too much redundancy, considering the badge is just below it as well?). Expect more photographs, specifications and pricing in the near future.