See also:

Cleaning the steering wheel and gear or selector lever
•► Thoroughly wipe with a damp cloth or use leather care agents that have been recommended and approved by Mercedes- Benz. ...

Problems with the SmartKey
...

Bar
Metric unit for tire pressure. There are 14.5038 pounds per square inch (psi) to 1 bar; there are 100 kilopascals (kPa) to 1 bar. ...