Battery OEM Mazda or OEM Volkswagen

i had my left side battery replaced about a year ago and i watched the shop (not a dealer) do it. the starter battery was not disconnected, the hardest part seemed to be lifting the battery out (fits tightley in there and isn't feather light).

Jack on my visit the battery was also replaced. Part# 000-915-105-CE. They also replaced two modules that were causing a drain on the battery.

The VW service called yesterday (I took my car in that morning) and stated the battery (driver side) was bad, and was replaced ($347, if not in warranty). Other battery OK.

Currently I actually own a 2005 V8 and it has been just short of a nightmare to maintain. First was the battery($400) then the headlights($200) then the Thermostat($900), then the horn($80) then timing belt, water pump, stripped drain plug, etc all within a year.