So I have no problem supporting vendors, especially for a niche market vehicle, because you could possibly have only one or two vendors for parts and/or service and it's good to throw them some money to keep them in business.
What I do have is a problem with other people who own the same type of vehicle that are insistent on using one specific vendor and it's the end-all-be-all for parts.
It really makes for petty arguments when you try to tell your make specific forum that you found the spark plugs or oil filters that your vehicles use, for sale at a box store or online and the devoted sweep in and start telling everyone that the Vendor carries those same parts and that we should only buy from them or kittens and puppies will die or the earth will break off its axis.
There's no good way to deal with these people, but it's getting annoying, especially for people who may be new to the cars and are trying to find out if they are getting a good deal for a part, because, you know, some people are money conscious even when it comes to our cars.
Oh well, rant over. 
