The Mercedes CLS is arguably the car that started the “four door coupe” styling trend. (I know, it has two too many doors to be called a coupe). Now in it’s third generation the CLS has another trick up it’s sleeve: a standard hybrid system. Although this hybrid (or mild hybrid, whatever you want to call it) cannot drive the car on the motor alone, it does provide a horsepower and torque boost at certain RPMs and most importantly allows the air conditioning to run while at stoplights, something you can’t do in most “mild hybrids” out there. The result is an efficient luxury sedan that trades practicality for style. The only downside? Mercedes makes an E 450 that’s basically a more practical CLS with an MSRP $10,000 less…