Here's a model-by-model breakdown:
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Overall it looks like VW has relatively few engine failures, but can't make a transmission worth a damn and/or has other powertrain failures. The Jetta has a sample size of almost 10,000 and scores a 30/100 on overall reliability, or "well below average", while the Beetle might be the second-worst vehicle that site tracks overall (next to Mini Cooper). The Rabbit actually gets a fair score of about 60/100, which is (slightly above) average.