Hi mrLauderdale,
I, like you, found a very nice clean example of a 2018 Expedition for our family hauler. I, like you, also researched endlessly and therefore, I purchased at a Ford Dealership that was selling a vehicle that fit my criteria as a Gold Certified Pre-Owned.
They fixed several little issues, put new brakes and tires front + rear on, and replaced the sunroof guide rails (another somewhat common issue) under CPO inspection PRIOR to purchase. During purchase negotiation, I was able to add on a Ford PremiumCARE Extended Service Plan (the highest "tier" of warranty) out to 10y/100k from in-service date, for approx. $2300.
Since then, I have had several things repaired that were covered under warranty, including:
-3rd Brake Light - had several LEDs that failed.
-Rear hatch GLASS struts - they were weak and the glass wouldn't stay up in cold weather.
-Thermostat + housing/assembly - vehicle was overheating (actually since the day I picked it up, long story). This one took a fight as the dealer way misdiagnosed but once they took my word for it, and replaced it/solved the issue, it was covered.
-All 4 TPMS sensors - one was giving no-reading shortly after purchase. They replaced it under warranty, and while it was at the shop, 2 others failed (go figure). They went ahead and replaced/covered all four.
It is going in again in (2) weeks for:
-TSB related to transmission - new valve body & CDF drum to fix delayed engagement into reverse and an intermittent firm shift into 5th
-Camshaft phasers - they produce a loud knocking noise at warm idle and produce a noise at startup
While they are there, I am going to have them replace the (2) heater hose assemblies out of pocket (not eligible for warranty coverage anyhow) as there have been many reports of these leaking with age, especially after being disturbed like during a phaser job. I am also going to have them do plugs and coil boots out of pocket, as I am just shy of 60k miles and that is the proper interval for EcoBoost engines.
I suspect the vehicle will last us many years, and all of the common problem areas will have been addressed as of (2) weeks from now. Going into a purchase as an educated customer is key. This is the first extended warranty I have ever purchased but as of writing, it will have paid for itself close to 3x in 6 months of ownership. For what it is worth, the "Gold Certified" warranty would have covered most if not all of these repairs, as well, but I wanted the coverage extended out.
Alas, finding a good dealership and a good service department is the first major hurdle. If you can secure that, ownership is a breeze. They are truly great vehicles and we really enjoy ours. It is the first used Ford product we have bought in years, after a long line of brand new Explorers and F150s, so I am familiar with the product and our dealer support network, which gave me a leg up I think.
Good luck with your hunt!