In the past few weeks, my partner and I are more set in living in Europe on a semi-retired basis, an idea that has been mulled about for a decade but set in motion due to a series of recent poignant events.
Residency (and work if the desire arises) is not an issue, other than for the bureaucratic process, as she possesses citizenship of a 1st tier (as in no migration restrictions for citizens of 10 of the last 12 entrants) E.U. nation.
Location:
We like someplace by the sea, or at least water. Requirements: temperate climate - not too cold in winter and not too hot in summer - somewhat similar to where we currently live. She has thought of Italy but I have warned her that the hot winds from the Sahara would make life too difficult for us. Her parents' native country is out as it gets too cold, is not by the sea (though the village is by a nice alpine lake), and is far too close to her many kin for her liking.

I have always liked western France, probably Morbihan and south to the mouth of the Garonne (or is it Gironde) or maybe the Pays Basque (Landes is too boring). If Spain goes bang, I would imagine there may be places in northern Spain that may go cheap but my French is better than my Spanish and we feel more comfortable in France. Any suggestions?
Car:
Yes, we do need one. For people who may be somewhat nomadic until they find a place they want to live, where is a good place to buy cars? I understand Belgium is a good place to buy cars cheap as it is the most competitive, or was at least initially? How would registration and insurance work for those who will be nomadic at first? There are addresses we could use but there is the legality issue. And how would one get a drivers' licence if one is nomadic? As for brands, we are looking for an affordable and reliable brand that where service is widely available. Would any of the major brands (i.e., VW, Opel, Peugeot-Citroen, Renault, Fiat, Ford) be o.k.?
Health Insurance:
We probably can keep our local (and fairly affordable) medical insurance coverage which does not cover well outside the jurisdiction. Coverage for int'l travel is extra and limits one to how long one can be out. We could buy into the insurance scheme of her parents' country (though it is quite a bit more expensive). How portable is European health insurance if one doesn't actually reside in the country where it it purchased?