I am looking for a GLK 350 or a BMW x5 series. Among the two, which one is the most reliable?

If you get a manual car i would say BMW but if you get a Automatic Mercedes has always made a better automatic transmission but they are both great cars. The X5 in a manual transmission will have little to no problems and the Mercedes in automatic will be a good car also its just up to your preference.

Thank you for your answer, I appriciate your input. What about fixing cost? Everyone tells me: They are to expensive to fix, bla, bla, bla !!! . How much of that is true?

Fixing costs are higher on a BMW and a Mercedes generally they are close to the same Mercedes will be a little more than a BMW, but not by much if you compare a Honda repair to a BMW repair itll be more but its always expensive to get repairs from the Dealers shop. I would avoid Kompressor Mercedes we just had a 2000 dollar repair because a cheap part went bad and oil got where it shouldn't you get extra power with a Kompressor brand mercedes but if your not looking for power why get it. If you go to a not franchise shop the Mercedes may be cheaper to fix but you still have to pay the parts and BMW at a shop thats not owned by the franchise will be cheaper but can't always fix everything you want to make sure the shop you go to is a good quality before you take your car there itll be cheaper but you want the proof that they are good and not some cheap place doing cheap work thats not quality.

Thank you for your answers. The reason why I am trying to get some opinons in this matter, is because I owen a Fiat Gucci 500 and that is a car that is not going to do well in Winter. Could you please tell me other SUVs that maight be as reliable as the two I have mentioned above?

Lexus Rx series and Acura MDX's are great cars since you seem to like the luxury car and if you want big you've got chevy products like the Tahoe and the Suburban.

Tria, I was checking thru autotraders and I saw a 2001 Mercedes M series, price 3500, it has 146000 miles. I saw the pics and it looked in really good condition. I called and the owner told me that the car is cheap because the air conditioning does not work, the compressor needs to be fix. Do you think is worth it?