I drive a 2003 Perodua Kembara DVVT and it had no cabin air filter.
Most older cars also didn't have a cabin air filter.
As the Kembara was a rebadged Daihatsu Terios, I assumed that the cabin air filter compartment didn't make to the Malaysian model due to less strict regulations and probably just for the cost effectiveness.
Well it had a botched up one I taped on a few years ago.
So I decided to upgrade the old botched up one with a more proper one.
Thus making this mod applicable to some older cars.
Step 1: Measuring
Measure the dimensions.
You can't usually buy and just bolt on these kind of stuff. This is a custom job.
So you'll need to measure the place you want to put your cabin air filter.
Usually the air intake of the aircond is where you want to install the filter.
It's located usually behind the easily detachable glove box of your car.
Take measurements and make sure you have the tolerances measured too.
Step 2: Gather the Stuff Needed
You get the filters first.
Buy it from eBay. It's 2USD.
Just search for 'cabin air filter' at ebay.
El' cheapo me got it for $1.75 a while ago.
2 weeks later to a month you'll get the sweet stuff in the post.
Get some scissors and a hot glue gun.
And get some materials, cardboard is good.
But I'm using a plastic board because I got it for free.
Step 3: Making the Filter
Cut up the filter and reshape it to your required dimensions.
This is important.
You have to measure the exact dimensions first.
This is because if you screw up the dimensions you pretty much screwed up for life.
Like they say 'measure fifteen times and still screw up bwahahaha'. NO
Cut the board to act as the size guide for the filter and glue the filter's sides to the board.
Tadaaaa... A custom size filter finished.
Step 4: Making the Adaptor
The adaptor will act as a housing for your cabin air filter in the car.
Much like your house that encloses you. Wait, that isn't comparable at all.
The design, figure it up yourself. I did.
All cars are not designed the same. So you really have to figure the custom shape for your own car.
Unless you have the same car as me.
Tape it up.
Just make sure to test fit the filter first.
I made mine to have a flap that locks similar to a normal commercial cardboard box would so I could open and close it easily.
Step 5: Installation
If you measured properly, the adaptor should fit just right where you wanted it to fit.
Tape the adaptor to the intake.
You could use double sided tape for this.
I didn't because the tolerances in my case didn't allow for it.
Tape it up properly.
Insert the filter in the adaptor and close the latch/door of the adaptor.
Don't forget to test the aircond.
Make sure air is not too restrictive.
In my case, it works great.
Step 6: Enjoy
There you have it, a DIY piece of imaginary thing that probably was omitted from the final design of the car due to cost and at your expense.
*The filter will only filter dust, airborne muck, hair and a bit of air pollution.
**The filter will not filter airborne viruses, foul smells, hatred, farts, your dirty feet smell or any deplorable facial expression.
***Enjoy the clean air