I have used the top end Interstate battery for my 124 E class with great success. Just got my last one for $85 + tax this summer (list is around $120). Interstate has been a US supplier of batteries for Mercedes. With that said, I am also familiar with the Autozone battery. It seems to have the same exterior construction and CCAs as my Interstate, as well as a great warranty. Can't beat it for the price. The Optima is also a great battery but like the O.E. MB battery is a little pricey for me.