Ordered these to replace all four of my door speakers in my 2008 HHR as 3 had quit working. I had to drill 4 small holes in my door frame to mount these as the HHR has a unique factory radio speaker assembly. Not a great deal of room for drilling the holes but there was enough to get the job done as long as you take your time and ensure where all 4 holes will be before drilling the first hole. The key was to ensure you were not to close to the edge of the speaker opening when drilling the holes.
These do not come with any mounting brackets or screws.
Sound: excellent, more than I expected from $12 speakers. I highly recommend these if you are looking for inexpensive quality speakers.
drill with small bit
4 sheet metal screws per speaker (I used extra screws I had which were actually drain spout gutter screws, worked great as they have a small tip on them with no threads which helps greatly with lining up the screws to the holes when installing the speakers)
Additional item used: wiring harness to connect the wiring connector to the speaker to prevent having to permanent solder connection in the event I ever need to remove the speaker for troubleshooting, plus I didnt want to deal with having to solder the connectors.