IMO, the entire survey is highly dependent on the replacement cost of the battery in 5-8 years, which isn't even mentioned in the survey, and which we have no good numbers for yet. The survey results will be colored by each individual's idea on what they think the replacement cost should be and is likely to be. If in that time frame it is <$4k (or insert your idea of reasonable cost here), many would consider it a wear item and/or even an upgrade (maybe 2nd/3rd generation batteries with more capacity or longer life will be available by then). The only way a warranty REALLY matters is if the batteries wear out very quickly (less than 5 years) and/or cost A LOT to replace (say $8k). If that is the case, not many would touch it with a 10ft pole with any less than 8 year 100,000 mile warranty, if not, 5 year 60,000 mile is probably enough for most and 8 year would only be a confidence booster. Also, if it does cost a lot and/or wear out quickly, does the replacement have an all-new warranty? The survey didn't ask anything about any of these issues.