DIY Interior Deep Clean | Garage Rescue Miata

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David S.
Update by David S. Wallens to the Mazda Miata project car
Feb 27, 2021

Our Mazda Miata’s interior had gotten fairly gross while sitting. You’ve heard this before but, yeah, we screwed up. 

Before sending the Miata to BSI Racing for its R&R, we wiped down the interior: Simple Green followed by Griot’s Garage Vinyl & Rubber Dressing. 

The interior looked pretty decent.

But, we thought, we should do a deep clean and get into the carpet and upholstery. Our hope/plan: a deep, DIY clean would keep us from needing to replace the carpet or rent a full-on steam cleaner. 

Step 1: Pull the seats for better access. In the Miata, this involves just four bolts per seat. For good measure, we first hit the bolts with some CRC Knock’er Loose penetrant. 

Step 2: Vacuum everything. And then vacuum again. 

Step 3: We hosed down the carpet and seats with Resolve carpet cleaner and agitated with a medium-stiff brush–not the stiffest but not all loose and floppy, either.

Step 4: Here’s where we learned that one can of that Resolve carpet cleaner isn’t quite enough for a full Miata interior, so we switched to Simple Green. It cleans everything, right? 

Step 5: As per the directions, we let the carpet cleaner (fortified with Simple Green) dry. Then we vacuumed. 

Step 6: We wiped down the vinyl seat backs with Griot’s Garage Rubber & Vinyl Dressing.

Step 7: What about killing any remaining mold? Some online searching turned us on to a product called Concrobium Mold Control that’s supposed to be tough on mold and easy on everything else. Sounds promising, right?


Here’s that promise:

Concrobium Mold Control effectively eliminates and prevents mold with no bleach, ammonia or VOCs. Concrobium works as it dries by crushing the mold spores at the roots and leaving behind an invisible antimicrobial barrier to prevent future mold growth.

So we picked up some from the local Home Labyrinth. Since we didn’t know how far it would go, we actually grabbed two cans about $10 each: an aerosol spray and a liquid spray. We hit the carpets and seats with the liquid spray–and admit we might have gone a little heavy.

Step 8: After cleaning the rest of the interior plastics once again, we bolted the seats back into the car. 

After letting everything dry, our interior smells like clean laundry while looking good–been a long time since the seats looked this black. (Sadly, they look a tad white in the photos.)

Is the mold gone for good? We’ll let you know if any returns. 

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DirtyBird222 PowerDork
2/26/21 3:10 p.m.

Awesome write up David! 

I have a fairly low cost method to doing that as well and not as many harmful chemicals in your face:

1) initial vacuum/wipe down

2) Fill a spray bottle with some mild degreaser (orange stuff) and hit carpets and non-leather/synthetic seats with it and let it soak for 15-20 minutes

3) Fill a 5 gallon bucket with a cap full of that sensitive skin laundry detergent (clear stuff) and warm water.

4) Grab a stiff scrub brush with a handle - take your detergent water bucket and start scrubbing in that degreaser to clean up those carpet and seats

5) Once you're done with that, grab your wet/dry vac and get to work getting as much moisture out of the carpet that you can. 

6) Repeat steps 2-5 if you have those tough stains in a light gray e36 M3 interior

7) For mold: A spray bottle with vinegar

8) Spray and let soak, get that detergent/warm water bucket and scrubber back out - go to town

9) Wipe up/vacuum and let dry - the vinegar should kill most anything in its path and the detergent should keep things smelling nice. 

I brought life back the light gray carpet in my E36 M3 that had all kinds of weird orange and brown stains. Looked brand new with this method

Vajingo Reader
2/26/21 3:50 p.m.

So does the interior now smell (reek?) like sinple green? I hate the smell of that and windex!

Allen Gage
Allen Gage
2/27/21 12:37 p.m.

Great article. I have used Concrobium and it is the real deal. When we sold our house, the attic had some mold in the rafters and the "preferred method" to kill the mold was to buy 2 gallons of Concrobium and rent a fogger to fog the entire area. It worked great and the buyer's home inspector said that that is how the pros mitigate mold.

BTW - Simple Green makes a version for cars, in a black gallon bottle, that has no smell, for those who object to the minty-ness. Personally, I like the scent, as my cars will sit over the winter and when I get into them in the spring, a ride through the country with the windows open makes it go away. It also has a tendency to help repel those nasty little critters that love to make your car smell really bad!

David S. Wallens
David S. Wallens Editorial Director
3/1/21 11:58 a.m.

I checked out the SDS for Concrobium when checking it out. IIRC, it's basically TSP and baking soda. 

I don't mind the smell of Simple Green, but now the Miata smells like a Miata. 

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