I ran across this Pin on Pinterest which said to use scrubbing bubbles to clean the carpet in your car! It actually works! Why has no one told us about this before? Just spray scrubbing bubbles on the interior, let sit for 5 minutes then spray the area with a spray bottle filled with warm water. Use a kitchen palm brush to REALLY scrub in circles. Soak it up with a rag or vacuum dry. Waa-la!
Neary Bernard put it to the test in her vehicle...she said "The before was caked on for about 4 years. Finally used this trick to clean it. I vacuumed, sprayed scrub & bubbles (let it sit), then sprayed water and scrubbed with a brush. Next trick I used was a portable rug cleaner. That really took up everything. As you can see in the after picture. I'm impressed."