First item, a weired noise when making a left turn on C300 2008, I took it in the dealer in San Antonio, Texas. They could not duplicate the problems. A squealing noise is still there. Second item, I asked for tires rotation. Tires were rotated but I didn't know if they were balance or not. All tires were at 26.5 PSI when I drove out of the service. Tire manufacturing recommending is 28 PSI in the front and 33 PSI in the back. I was not happy at all. Left a message to service manager (B.) Never get a call back from him. Does anyone have same issues with this dealership?

 

My advice would be this:

Find another dealership, even if it's further away from home.
You bought a new car, it's under warranty, and this is not acceptable.
They have to make the car right and you should tell them so.
Never leave a message for any service manager. Waste of time.
If you are not satisfied with ANY dealership, DEMAND to see the GENERAL MANAGER only.
He is the one who can make anything happen if it's going to happen at all.

PS> I'm not familiar with that particular dealer, but these suggestions come from personal experience
dealing with different dealerships all over the country. And all makes of cars.

Be sure the tires on your car (and I don't know about yours) are the exact same size tire.
Otherwise, they cannot be "rotated", which if directional, means moving them rear to front only.
Just a thought because mine are different sizes, but again, it's a different car altogether.

I'm not sure tire balancing would be covered under factory warranty. That's sort of a different issue altogether.
Usually, vibrations felt in the steering wheel or seats going down the road are tire balance issues.

 

Thanks for advice. I will contact general manager to help me out on those issues.