Wow, you reminded me of a phenomenon I experienced over a decade ago when I was running my 1-man speed shop. Folks would buy stuff from me, then shove it under their bed. I was lucky to get a 30% feedback rate. You mentioned buying stuff, but you'll get around to installing it later. Seems people buy parts they intend to install, but often either never get around to doing it, or do it so many years later that ....