So, couple things here that I will try and address in my post - forgive me if it's long. First, I want it known that I consider myself a racing collector. I don't have nearly the extensive collections as some of you, but I want to make sure it's understood that I'm not trying to give a racing set "baseball treatment". I know Billy K feels that way sometimes, and I assure you that's not what I'm trying to do here.
The Letterman sets are unique in a few ways. One major way is that some, if not a majority of them, are MANU sets - meaning the company intentionally produced fake memorabilia to include on these cards. I think those are a separate topic and as such, I'm going to ignore them here to focus only on MEM cards.
With Letterman sets, we know what the cards are spelling (or are able to figure it out, if it isn't a last name), so creating one long checklist is easy enough to do. Here, as noted in the last reply, we have no way of knowing what the individual associate sponsors are unless we find a 1/1 online or someone here has one (or more). That's really the big key here and the driver to how these should be listed. We could launch into a conversation about collectibility and the purpose that the manufacturer has, but that seems moot to me because we can't really be the interpreters of that.
Spaz, to your point about the images, they can still be tracked. If I have Liberty U and you have Axalta, and you add the images for Axalta to the Database, I can still go into the set, add the JP-WB card to my collection, use "Detailed Add" to add a comment that says "Liberty U", and then have the ability to add my own images, which will then appear when I go through my collection. These tools exist and are perfect for situations like this, in my opinion (just like that Bryce Harper card I made up earlier, where one card has a red swatch and one has a white one).
I know there will be plenty of disagreement with this, but I don't see how we can list these all out as VARs of each other without knowing what each one is.
My official suggestion would be to have one checklist with one listing for each driver, and a Note noting the PR of each driver as well. Release Notes for each set that explain that each driver has between 1 and x distinct patches available, all SN1. We can use the Comments on each card to keep a running list of each sponsor found - for example, on the Kurt Busch card, we can have a comment that says "10 Associate Sponsor cards produced. Known sponsors: Busch, Monster Energy.". Comments can be edited by the original user, so as we discover new ones, they can be added to the running list.
Side note - Panini and their considerations are often inconsistent. They routinely refer to subsets of the base set and parallels as their own insert sets, and that's not even considering the card number debacle. Also, I've been working on this for an hour or so (I keep getting distracted by work), so some of these points I've had to go back and edit to account for new posts.
I'll never quit collecting entirely, but I am downsizing. Check out my COMC store and help me thin out what I don't want so I can buy cards that I do want. See something you like? Send me a message on here, and we can knock the price down quite a bit. I'll even take a bit of a loss if it means getting you a card you really want.