Sounds like there is a hole in floor board?
 

My husband just got a 2006 very used hhr for me two days ago. So far Ive had a bunch of the more common problems for this car I guess? Key fob not working so my alarm goes off every time I try to unlock it, seats stained when I just look at them, wet passenger floor when it rains. But now Im hearing from the passenger side EVERY noise from the road. hit a bump, splashing water, the tires turning, the road in general with acceleration. Do I have a hole under the floor board or is this normal?? Obviously Im taking it in to the mechanic to get the whole thing looked at because Its used and theres just so many issues, but just wanted a little idea of if this is common or not.

OH! and also, when I hit a puddle I swear it sounded like it was coming inside the car and I THINK I might have seen my dash lights flicker a little. I dont know if Im being paranoid but I feel like my car is going to short circuit and fall apart from just driving in the rain.

In the order that you mention the issues here are some things to look at (and most problems can be easily fixed with common tools and the instructions from people here):

KEY FOB - Alarm sounding:
I gather you are using the key to unlock it - yes the security system will sound if you use the key - If you lock the vehicle with the inside button, I think it bypasses the alarm (but I may be wrong) - you really need to fix the key fob, and it really isn't that hard - read these two threads:
1) worn contacts in the fob: https://www.chevyhhr.net/forums/how-tutorial-library-21/repair-key-fob-remotes-worn-out-contacts-30813/
2) broken battery hold down: https://www.chevyhhr.net/forums/how-tutorial-library-21/keyfob-cold-solder-repair-22641/

SEATS STAINED:
yes due to the colour and material used, they can get rather nasty looking over time. Any good upholstery cleaner for a car, or for the home will bring them back nicely - the important thing to remember, is that the WHOLE panel will need to be cleaned (not spot-cleaning) else you will be left with a "ring" or worse.

WET PASSENGER FLOOR:
Being a 2006, there is a butyl patch (flexible plastic) seal underneath the cowl that covers the windshield wiper mechanism - the patch often wears out, and cracks and lets water into the cabin (check the cabin air filter located in the top of the glove box - if it is wet, the patch needs replacement) - see this for a fix - https://www.chevyhhr.net/forums/how-tutorial-library-21/fixed-my-water-leak-last-night-14263/ - if ignored, water can get into the fan motor and cause problems with the fan speed.

Other sources of water leaks:
A/C drain: https://www.chevyhhr.net/forums/showt...ght=drain+tube
sunroof drain: https://www.chevyhhr.net/forums/show...?t=770&page=29

Water leaks MUST be resolved as they can cause major problems with the electronics, and the carpets etc.. Focus on that first.

FLOOR BOARDS:
No, it is not likely you have a hole down there - but have a look inside each wheel well on the front and see if there is a big black piece of plastic that lines the whole wheel well - it protects the underside of the fenders and the engine bay's side.

How many miles are on the vehicle?

Thank you so much for the info! Im a bit more concerned now about the water, it seems like the prior owner probably neglected this issue. they neglected a lot of other things...Since its my first two days with it though, Im not letting it continue!

We are not very car savvy so Im going to show all of this to my mechanic to save him some time. The car has 116k miles on it. Ive tried researching how well these cars do after 100k miles but haven't come up with much.

So as for the noise, if the plastic lining is there the noise must be something else then? I havent had the chance to check yet but I do believe it is there.

Good luck with the issues - they actually are a pretty tough little car - so don't get discouraged. Our 2006 has about the same mileage and has been through a lot, and keeps bouncing right back.

Keep us posted and feel free to post any questions you might have.

Tip for you: at the top of the page is a SEARCH tool, and it works pretty good (was just improved) so give it a try if you are looking for a quick answer on something.

and WELCOME!!!! :welcome4: