BMW 228ix leased.
I checked out both MB CLA and C class. The new C is really nice. CLA is not bad. Beamer is different. It's a funner car to drive and everything is for the driver. I didn't really notice turbo lag on the turbo 4. It's got plenty power and it makes you go seek out curvy country roads. It's a fun car. I hope my mom likes it. But aside from all that, what made the difference was the money.
BMW uses a much higher residual value in its lease calculation. I did my research with TrueCar.com and had capitalized costs on hand. Dealers seem to accept that price and give you that discount. At similar prices BMW came out $175 per month less than MB. I couldn't believe it. And this is with paying just the first month payment. I didn't put any additional money down. Additionally, all scheduled services are covered for 5 years for MBW. You have to pay for MB. It usually comes out to about $500 a year for their scheduled services.
So it was no-brainer for me. I have a feeling I am going to "borrow" the car a lot.