Don't know squat about VW's and really don't care as this is about right to repair ag equipment not cars.
I farm and I will not buy a tractor with electronic controls. Both mine are pre 4 models and I plan on using them until I retire and will (I take excellent care of both). Interestingly, the market for a used pre 4 tractor is getting very tight as operators are buying up any used ones and people that have them are keeping them.
Both my pre 4 Kubota large frame ag tractors are actually appreciating in value and I could sell either tomorrow for substantial bucks. I won't.
Even Kubota plays the right to not repair. If you own a Kubota post 4 unit, you must go through a dealer and pay his shop rate for diagnostics as well as parts to repair. Kubota uses what is called a Diagmaster tool which accesses the proprietary ports in a Kubota post 4 tractor and you cannot buy the tool. In fact the dealer cannot buy the tool, the tool is 'leased' to the dealer from Kubota.
The access ports are proprietary so you have to have the tool to plug in. No OBD stuff here.
Both my units are purely mechanical injection, only 'electronic' thing on them is the fuel cut solenoid which is an electromagnet and easily replaceable.
Late model JD's specifically the large over 150 pto horsepower units have very complex electronics, my good friend down the road runs a large commercial seed operation and runs millions of dollars in JD late model equipment. JD has even went so far as to have sensors in the fuel and oil filters that sense oil and fuel parameters and send that information to the on board computer which in turn sends the data to the dealer. You don't change the fluids, the dealer tells you when to change and you use JD fluids and filters, no exceptions. Even the air filter is electronically monitored.
JD uses their Green Star on board positioning system to communicate with the selling dealer so it may do precision farming via GPS, it also is telling the dealer what the unit is doing, if the operator is abusing it (as in overspeeding the engine) and when service is due and then the dealer informs the owner it's service time.
Pretty wild and I get to see it in real time and I thank my stars I don't have a new post 4 unit. Not only do emissions tractors suck but you cannot repair them, especially any emissions related issue. Only the dealer can and at his rates and with OEM parts.
Kubota is as bad as Deere almost. I imagine CNH is the same deal but not sure as I don't know of anyone that runs CNH tractors. I do run NH hay tools however.
Far as government farm subsidies go, farming is a very expensive occupation with high inherent risks so the Farm Bill was legislated to keep farmers from going **** up during bad years. Not a free ride by any stretch and if you don't farm, don't criticize it as you don't understand how it works.
