Sir, the best way and most effective is Try first to clean with a cloth and remove all the dust, then try car shampoo with sponge not cloth, after washing your interior with car shampoo, but donot put the sponge on electronic devices such as CD Player, AC Knobs, front wheel assembly/indicator assembly, only the body. and donot wash under sun because after washing the sun can.
Then you can apply a cleaner its not a polish but its a cleaner, it does not give you a shine but give you a factory outlook. The way to use the below product is to spray evenly after covering glass/meter parts and other non-plastic products. The try to clean with a soft and clean cloth.
After you apply 02 to 03 times you will get your factory shine, because most of the products gives shine to interior but when the car comes out infront of sun the polish start to dry and ruin the original interior finish.
Below is the product picture, It will cost you around Rs 200/- max.

