what was the easiest car or truck ever made for a shadetree mechanic to work on.
I was going to say the old Chrysler slant 6 with a lot of room under the hood, except for the points. The old 60’s Chevy six with the points you could adjust through the window on the distributor then was probably it for me.
Ford Model A. Everyone who owned one was their own mechanic.
Here’s some ideas
4 cylinder inline
engine longitudinally mounted
OHV design . . . no variable valve timing of any kind
Timing chain
serpentine belt with automatic tensioner . . . no adjustments to mess with
Rear wheel drive
Automatic transmission
1-piece drive shaft
Solid rear axle
EFI . . . therefore no carb to mess around with
NO points and condenser . . . therefore not ancient
OBD 2 compliant . . . therefore fairly easy to retrieve codes and diagnose
disc brakes front and rear . . . no shoes to adjust
The parking brake function is built into the rear caliper . . . again, no shoes to mess with
Hubless front rotors . . . don’t have to mess with bearings when replacing/machining rotors
Model T
I think the early 90’s 4 cylinder fuel injected Toyotas are the easiest of any I’ve worked on. First off, they are very reliable, so there’s little work to do. The routine maintenance is all easy to do. Well, except for the timing belt. When these cars fail to work from time to time, they are usually easy to diagnose and repair, and inexpensive to fix, to boot.
A Ford Ranger pickup with manual transmission and no options is pretty basic. The inline engine is easy to work on.
@GeorgeSanJose, I agree Toyotas tend to be very reliable but they are not without their weird foibles:
When it comes to trucks, Taco oil changes are a straight up pain. The filter is up, dangling right over the half shaft so you have to take skid plate off just to get to them and then they drip all over the place - an unholy mess. The skid plate bolts are fragile, not stainless, so totally rot out very quickly and the thread they fit into beats loose.
It is the most hokey design for a nice truck like that, imo.
The spark plugs on older 6 cylinder Camrys are near impossible to get to. They are right next to the fire wall. You have to unbolt things like the air intake manifold to get your hands in there.
Early 90’s Honda Civic is one of the easiest I’ve ever worked on. Everything’s nice and accessible. The motor’s light enough that a guy who doesn’t work out all that much can lift it out of the car by himself if he harnesses himself to it with a rope.
About the only difficult thing to do is to remove the shift linkage pin (which Honda guys not-so-affectionately call the “bitch pin”) but once you know the trick to that, it’s not that hard either.
Every time I tear into my MR2 or my Acura, I wish my CRX was the one that broke instead. 
The EASIEST was my Chevy Vega. Very simple…only needed a 1/2" and 9/16" wrench to take about 70% of the vehicle.
The problem was that I had to do a LOT of fixes for that vehicle. It was one of the MOST problematic vehicles ever made.
For sheer simplicity you can’t beat the now antique 4 cylinder flatheads.
I don’t know if it’s the simplest car in the modern era to service, but my daughter’s 2005 Mustang with the 4.0 is pretty clean and unobstructed. Even the spark plugs are a 10-15 minute job.
How about a Ford Maverick?
Ford advertised that the car was so simple to service & repair that, “even a stewardess can do it”.
Can you imagine a company using an advertising slogan like that nowadays?
even a stewardess can do it
A line I always remember from an old magazine (Car & Driver, I believe) reviewing the then-brand-new Jeep Wagoneer was “And the automatic transmission means that even a woman, with proper savvy, can drive it with no trouble.”
Another personal favorite was a Popular Mechanics article on testing lawn tractors. They showed the test team, which had a female member “on the theory that if there’s a way to break a piece of machinery, a woman will find it.”
How times have changed since the 60’s.
Years ago, in the 70s, I was quoting on a government maintenance contract. This government had an “affirmative action” policy which meant that natives, visible minorities, ect. had to be hired where available.
However the bid document also had …, “women, and other disadvantaged groups”. My secretary, who could stand her ground and wore cowboy boots (very stylish ones) to the office, said "who the H…l do these guys think we are?
Straight six chevy motor used in a bunch of GM cars from 1962 - on… Nothing you did to it made it run better or worse. The carb could be rebuilt in 30 minutes, points and plugs changed in 20. Put in electronic ignition, add a manual choke and you wouldn’t have to do any service to it except oil in 200,000 miles.
Yeah, I guess stewardesses (now flight attendants) have a better lobby than cavemen do
Actually it wasn’t a trick question, but here’s a “trick answer”: the simplest, easiest to work on car isn’t a car, but a motorcycle! Specifically:
- Gravity-fed carb
- Air cooled
- One or two cyl max
- Naked bike with no plastic cladding/“tupperware”
Specifically, either a KLR 650 or one of Honda’s CB-series. A pre-EFI Harley would fit the bill, too. About as hard to work on as a (scaled-up) bicycle with lawnmower engine.
- Gravity-fed carb - Air cooled - One or two cyl max - Naked bike with no plastic cladding/"tupperware"
Except for the last point, you’ve described a Trabant 
Honda CL90
It’s a third world favorite for a reason.
late 80s S-10 with the Tech 4 and 5speed-Kevin