I got one from Battery World last year. I think they have two that will fit, same physical sizes, but different CCA's. i opted for the cheaper off the two as the golf isnt that hard to crank over i figure the extra was a waste of money better spent on batteries for my other cars.
Like JustCrusin said, its an easy swap, should only take about 5 mins. i spent 4 of the 5 mins getting the fuse panel off.
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