Responding to my own post to clarify. There would be a large number of options, every possible combination of these three categories: Nation, Decade, and Vehicle Type. Having a poll for each category would not work, and combining the top votes for each, as then you may get vehicle combinations that no one wants or redundant vehicles. Every user would have a large number of votes, 10-15 most likely, noting that this is a list with hundreds of options. Hopefully the most needed categories would get filled in.