Finding the source of the stink

[ThisStinkinVitara]

So, just before Christmas 2018 I bought this beautiful black Grand Vitara. It was beautiful. Everything just worked! It was quiet, comfortable, reliable AND robust!

Just to qualify my gushing, my last car was a 130,000 mile td4 Freelander1 - which I also loved, when it worked.

Anyway, it soon became apparent that my lovely new car had water ingress issues.
SHE FREAKIN STINKS.
At first I thought someone had blown chunks in the back seat so I thoroughly cleaned and disinfected the seats and carpets.
Then I thought it smelled of dairy so figured maybe a baby had projectile vommed all it's milk everywhere. Needless to say, having spent 10 hours scrubbing and disinfecting every interior surface in the car, she still stinks.
All footwells smell a little funky.
I can't find any wet spot or puddles (unlike my old Freelander/aquarium).
The rear footwells seem to smell a little worse than the fronts but don't get wet.
Ive had the rear seats out and cleaned and disinfected all the carpet (then spanked an entire bottle of Fabreeze in there).
The boot carpet is completely dry and doesn't smell

So I guess what I'm after is some advice on whether these things have any common leak/stink related issues.

Your thoughts?

[timwilks13]

Has something maybe crawled into your heater matrix and died? Happened to a mate of mine with a squirrel, just sat there rotting blowing a stink into the car

[ThisStinkinVitara]

I hadn't thought of that, haha!

It's gotta be worth a look. I'll check it out.

[ThisStinkinVitara]

I think the smell gets noticeably worse when I'm driving and switch off the air-conditioning. I wonder if the drain might be blocked.
Anybody able to shed any light on where the drain underneath the car might be....?

Tar.