Ask HN: What Happened to Competition in Travel?

Recently I was looking to book a rental car for a family trip. I was looking for a larger vehicle (6+ passengers) so we could take one car. Minivans are completely unavailable and even with high gas prices SUVs are running $200+/day. I searched the usual travel aggregator sites (Expedia, Kayak, Priceline) and prices were identical. The only interesting alternative that came up was Turo.

Does anyone have any suggestions for finding rental cars?