Don't know if it's already been posted elsewhere, but another German MK8 review is out.
ComputerBild Spiele: Sehr Gut - 1,43 (~9.1/10)
Summary (liberal translation) at the end of the review:
Difficulty of getting started - 10/10
"No matter if young or old, Amateur or Pro Driver - anyone will easily understand the game"
Graphics/Sound Quality - 9/10
"Animations for even the smallest details, immense profits from the jump to HD. Excellent music."
Controls - 9/10
"Motion Controls are fun, Menu presets are sadly missing (no idea what they mean with this)"
Single Player - 8/10
"Starts relatively easy, the new tracks are awesome. Not as much fun long-time."
Multiplayer - 10/10
"No matter if with two or up to four players - clearly the highlight of Mario Kart 8"
How well does the game run?
"No forced installation, short loading times"
Score: 1,43 (9.1/10)
I took pics of the summary as a proof, but won't post them here due to the no-scan rule. Will happily provide them to a mod if asked for^^