The first sentence is a greeting in a German business letter. The correct way to write it is: Mit freundlichen Grü?en. That is, "with friendly greetings"
The second paragraph is in English. Meaning:
For those who don't speak German - you can actually say thank you "At my address" to the Mercedes-Benz team Interested. They will send you Kimi Raikkonen's autograph (famous F1 driver Jimi Raikkonen) and more information about the racing circle. The letter is on the letterhead of (Mercedes-Benz) Logo on stationery.