Improved sound for relatively low cost
2015 Toyota Prius
Replaced stock non-JBL front door speakers with a pair of these speakers. Still using stock base head unit ("Display Audio"). Supplied Metra adapter was a perfect fit for existing holes in car door (after drilling out rivets), but screw holes on speakers were not a great match for adapter. 3 out of 4 holes could be used roughly, 4th had to be drilled new in adapter. Harness connector did not slot into Metra adapter hole, but was able to enlarge hole in adapter slightly so it fit snugly.. Sound clarity is definitely improved, though overall volume is slightly less than stock speaker and bass "feel" is about the same. Sections of music where there was significant distortion before with the stock speakers are much clearer now. I still hear some distortion at the high end, possibly the stock squawkers now standing out. For the price, upgrade was worth it.
Pros: Noticeable improvement for the price with no other upgrades.
Cons: Required some small modifications of the Metra adapter to make it work; volume is slightly less than stock speaker at same level on head unit.