Why doesn't the Beltway press treat Limbaugh with same disdain the automotive press does?

Did you see Motor Trend's takedown of Rush Limbaugh? It came after the automotive bible tapped the Chevrolet Volt as its prestigious Car of the Year. Limbaugh then predictably lashed out, reading all kinds of politics into Motor Trend awarding an environmentally-friendly electric car its highest honor.

The right-wing talker declared the motoring mag had lost all credibility with its Chevy pick. (Limbaugh seems oddly obsessed with seeing the American automaker fail.)

Motor Trend's response? Priceless:

Back to us for a moment, our credibility, Mr. Limbaugh, comes from actually driving and testing the car, and understanding its advanced technology. It comes from driving and testing virtually every new car sold, and from doing this once a year with all the all-new or significantly improved models all at the same time. We test, make judgments and write about things we understand.

...

You've made two king's ransoms by convincing legions of dittoheads to tune into you every day. I wonder, do you ever ride in anything that's not German or Anglo-Saxon? Do you have any idea how powerful IG Metal is, and of the size of Germany's social safety net?
The dismissive tone throughout was dead-on. I just wish more media elites inside the Beltway would treat Limbaugh and his avalanche of lies the same way.