Older cars will still come provided with a factory cassette head unit, if the previous owner didnt listen to CDs. Once CDs came out, everybody replaced cassette tapes with them, since it provided far better sound quality. If you still listen to old school beats on your tape deck, you notice in the background a hissing or crackling sound, it is because the head inside is dirty. Overtime, after constantly inserting and ejecting cassettes daily, the film inside the cassette will transfer dust and dirt onto the head. Since cassette decks for car audio are no longer produced, you cant buy a new one to replace it, so it is not worth throwing it away just yet. This problem can be resolved by using just a cassette cleaning kit, which is available to purchase from all leading electrical retailers.
1) The kit will come supplied with a cassette tape and a bottle of cleaning solution. Remove both items from there packaging. Look at the top of the cassette where the film goes, you will notice that it is a white color, instead of the brown color you usually see. This is because there is nothing recorded on the film, its purpose is to only transfer the liquid onto the head.
2) Remove the cap from the bottle. Squeeze the bottle gently and pour a sensible amount of cleaning solution evenly across the film. Once you have done that, screw back on the cap to prevent it evaporating or spilling out.
3) Insert the cassette into your car tape deck. Once inserted, press the Forward button found on the front panel. This will allow the motor to spin the cassette film really fast. During this process it will touch the film on the head, cleaning all existing dust and dirt.