I've told this story before, but I like telling it, so here goes.

I once went shopping for a Mustang Cobra, back when they were cool and I was young and into those kinds of cars. The local Ford dealer had their new car lot next door to the used lot, literally separated only by a driveway.

I went to look at the 2004 Cobras they had a half dozen of, and they were marked down (IIRC) $8000 off MSRP. I thought "Cool, the 04 is no different from the 03, so I wonder what I can get one of those on the used lot for." And walked over to look. The 03s were priced higher than the marked-down price on the 04s a couple hundred feet away. At the same dealer.

I brought it up with the used car manager, incredulous at what he was asking for the used ones. His response was "Yeah, go buy one of the new ones, these will sell just fine." I asked why and he said there is a whole class of buyer that won't even look at new cars. That the new car market and the used car markets are not in fact sharing the same space, even if it seems like it would make sense for people to cross-shop. So he priced his used cars at whatever the market would bear, which turned out to be higher than Ford would unload the new ones for.

Does this happen often? Perhaps not. But over the years I've bought new cars on several occasions where the used equivalent was going to save me a whopping $3-4K for a car that was two or three years older and with some miles. It did not make any financial sense whatsoever to buy the used one for such a small discount.

I was literally in this situation this year. My parents needed an upgrade, and as I was researching it, the 2 year old used cars were just 1-2k EUR cheaper than the same model new with a slight discount. Of course we got the new one, if only for having the full warranty period.