Vacuum (usually shop vacuums are the best for this type of work)
Remove all the floor mats, and shake them outside of the car to remove any dirt.
Vacuum the seats, behind, and underneath. Make sure to get the crevices where the dirt sticks into.
Vacuum the floor.
Vacuum the floor mats, then place them back into the car.
If you have any fabric that is stained, you can use a damp towel and a dime size amount of fabric remover.
Work it into the fabric.
Using a damp sponge rinse the shampoo. Then allow it to dry.
Using window cleaner and a paper towel to clean all the windows. If you have tinted windows you need to buy a window cleaner that is safe for tints. If you don’t want to buy window cleaner you could make your own. Just apply a drop of dawn soap into a bucket of water. Then wash your windows with the solution and a rag, rinse off with clean water. Use a paper towel to dry the windows. This solution is safe for tinted windows.
Wipe the dirt from dashboard and doors with a damp paper towel.
Spray some vinyl protectant once or twice into a rag. Then softly wipe the dashboard, doors and anything that is vinyl.
Give it a few minutes for the protectant to air dry.