Local computer file service records storage methods

I have been stroking all my car records in hard copy file folders. After moving many times over a 10 years stretch, I started scanning and storing everything on my computer (with backup). So now I have a huge collection of PDFs stored in car specific sub folders. I tried to maintain additional sub folders to separate self work vs dealership/shop work. But ended up just dumping everything in the car folder. 

I am not a fan of "cloud" storing my files. But other than just getting back into my windows explorer folder discipline, I can't seem to find an app to allow me to organize and properly store PDFs of service documents locally. I find many apps for gas prices and mpg tracking and service reminders. 

I tried to read up on SQL lite, Andromoney, and other things that looked like database storage options for Android. At this point I can't seem to find something that can help me store PDFs in set sub folders and allow me to search for service type performed. 

Any ideas? Personal experience?

What you want is referred to as enterprise content management.  Basically it's a mechanism by which you can attach metadata to "big data" to categorize, search, reference and archive data which isn't stored in an structured format or database.

Xerox Docushare is the big name in that arena, and expensive, but there may be similar applications for the home user. It's been a while since I looked at those products.