I hear you.
Some merchants extend warranty to current owners of their tools, not just the original purchasers/owners, and proof of purchase is not required, nor is any kind of registration needed. Good examples include Lie-Nielsen and Veritas/Lee Valley Tools. These are the kind of company that is customer-oriented, and the kind that's a joy to deal with. Often, the experience of after-sales service counts more than anything.
Ridgid registrations can be made on Ridgid.com and Ridgid.ca, and it took a bit of digging before I could retrieve my customer ID, which is what my local authorized repair dealer requires for free repair service. I had the original receipt from HD, but it wouldn't cut it.
Touch wood. None of my Festool purchases (7 of them, and properly registered (I think [unsure])) has ever needed any service.