A used Mercedes can negotiate a pothole like a tank takes a molehill. That's why you'll see Benzes serving as taxis on the toughest streets of Africa, Asia and Latin America. Maybe that explains their popularity here. The last-generation Es go for a little more than $20,000. This is for a top-line luxury car with relatively low mileage and a bulletproof motor. The caveat? Dealer service charges will make you weep. Regularly scheduled check-up and oil change? $400. Four-wheel brake job? $1,000. Staying away from the dealer? Priceless. Search Yelp!, Citysearch and other sites and you'll find that this guy stands out: Enrique J. Rodriguez. His Mr. MB Motors in Tarzana is widely praised for honesty and price. That oil change, for example, will cost less than $100, in most cases. Rodriguez has been working on the three-pointed-star cars from Stuttgart since 1964 and worked at dealerships in Cape Town, South Africa, Beverly Hills and Encino. He knows the cars' German quirks. 5557-A Reseda Blvd., Tarzana. (818) 708-8086.