The best replacement for parts is oem parts.

The best alternatives to parts are rated as following:
★★★★★  oem parts
★★★  aftermarket
★★★  aftermarket parts
★★  autozone
★★  substitution
★★  auto zone
★★  components
★★  eye
★  ar15 parts
★  commodore
★  girl parts
★  oem
★  user controls
★  microscope
★  not working
  moog
  statesman
  accessories
  new
  middle parts

Your alternative for parts is not listed? Suggest!
Speaking about parts, one probably shouldn't forget about bones.

Other search terms related to parts and their ratings are:
★★★★★ bones
★★ adipose tissue
★ label of frog
You have in mind a companion for parts and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of parts in all years. Click on graph for more.
parts
oem parts
aftermarket