Krzysinho

Will rims with these parameters be suitable for the GLK? And if so, what tires would be good?

9x20 ET 32
10x20 ET 45

I left the rims from my previous car

Odd Piggy

Largest original rims listed are 8.5x20 ET 45 and 9.5x20 ET 57. These rims will move the tires out 12-13 mm from the original setup plus 6.25 mm because they are wider. That may cause fender interference problems, especially on the front wheels. Tire size also enters into this determination. If the GLK is lifted there may not be a problem. Check with a tire retailer to see if these wheels with your tire selection is suitable.

calder-cay

You should clarify what you drive. You joined a couple days ago and profile shows:

Vehicle(s) I drive: Mercedes C32 AMG

If a GLK, you should specify the year and model.