Seems to be a good buy for an AGM 48 series battery at Tri State Battery Online Catalog
( free shipping )
My roadster had the previous version DEKA battery when I bought it, I have had NO issues, and this one is the newer technology Absorbed Glass Mat battery.

9AGM48
[9AGM48] $169.95
Click to enlarge AGM European Performance Battery

European Performance Battery

9AGM48 - AGM Battery
The Deka AGM Performance battery will fit many European & Domestic vehicles including: Audi, BMW, Chrysler, Jaguar, Mercedes Benz, Mini, Porsche, Saab, Volkswagen, Volvo and many other vehicle makes!

• Meets OEM AGM requirements for exact fit replacement
• Electrolyte absorbed by micro-porous glass separators eliminates acid spills and terminal corrosion
• Tightly "packed" construction and calcium reinforced grids provide greater resistance to shock and vibration
• Provides plenty of starting power at lower temperatures
• True maintenance-free performance means longer life with hassle-free service
• Superb dual purpose design delivers excellent starting and accessory power
• High porous separators lowers resistance and increases power

Specifications:

• Cranking Amps 875
• Cold Cranking Amps 760
• Ah Rate (20 Hr) 70
• Group Size 48/91

Dimensions:

• Length 11"
• Width 6 15/16"
• Height 7 1/2"