Thank you for posting to this forum, mike4Ski!
If you are asking a question please make sure to include any relevant information along with the Year, Make, Model, Mileage, Engine size, and Transmission Type (Automatic or Manual) of your car.
This comment is automatically added to every successful post. If you see this comment, your post was successful.
Forum users that have been verified will have a green background and an icon in their flair.
PLEASE REPORT ANY RULE-BREAKING BEHAVIOR
Rule 1 - Be Civil
Be civil to other users. This community is made up of professional mechanics, amateur mechanics, and those with no experience. All mechanical-related questions are welcome. Personal attacks, comments that are insulting or demeaning, etc. are not welcome.
Rule 2 - Be Helpful
Be helpful to other users. If someone is wrong, correcting them is fine, but there’s no reason to comment if you don’t have anything to add to the conversation.
Rule 3 - Serious Questions and Answers Only
Read the room. Jokes are fine to include, but posts should be asking a serious question and replies should contribute to the discussion.
Rule 4 - No Illegal, Unethical, or Dangerous Questions or Answers
Do not ask questions or provide answers pertaining to anything that is illegal, unethical, or dangerous.
PLEASE REPORT ANY RULE-BREAKING BEHAVIOR
I am a bot, and this action was performed automatically. Please contact the moderators of this forum if you have any questions or concerns.
The dealer
Just clean it really well and put a small bead of some RTV on there. It’ll be good, waterproof, and if necessary you can remove it later.
Torrance said:
Just clean it really well and put a small bead of some RTV on there. It’ll be good, waterproof, and if necessary you can remove it later.
This. I came in here to suggest the same. This falls under the “repair vs replace” category
@Finley
Definitely. It looks like a pain to replace anyway.
Torrance said:
Just clean it really well and put a small bead of some RTV on there. It’ll be good, waterproof, and if necessary you can remove it later.
That same piece broke on my old 2003 4Runner. Noticed it would leak water through there. Just went ahead and covered the whole outside with clear silicone 
problem solved
@Finley
Just be careful if it’s the metal tubes, they love to bust open when you squeeze them. Some work slacks and a shirt of mine still have grey goop all over them because of this issue
Unfortunately this is going to be a dealer-only item. You can check Mazdaparts website or any other OEM parts website, order from them, or get the part number then search other websites. It’s most likely going to be that whole rubber hose assembly. You will not find the clip.
Go to any junkyard near you and pull it yourself from a similar car.
I had the same problem with a Saab, RTV didn’t work for me.
I don’t really remember what I did, but I think I pulled down the rear of the headliner, found the clip, and put it back on eventually.
You might look at a pull-a-part junkyard and snag one. I bet a lot of Mazda 3 hatchbacks use that same clip.
If that doesn’t stay in because the fingers on that white piece are broke, it’s new harness time. Try a salvage yard, they probably won’t want to get it for you because of the labor to remove it from the hatch.
online
Dealership
Ask on the 3D printing sub