36 more auto manuals added

36 more auto manuals have been added to the site recently, for the following brands:

Buick:
   - 8 owner’s manuals
   - 5 quick reference guides

Cadillac:
   - 7 owner’s manuals

Ford:
   - 8 owner’s manuals
   - 3 quick reference guides

Nissan:
   - 2 owner’s manuals
   - 1 quick reference guide
   - 2 maintenance and service guides