Did you ever think you would miss having a cassette tape player in your car? Anyone with a car built between the mid 90's and late 00's sure does. It was so easy to buy a cassette to 3.5mm audio adapter back then and your CDs or MP3s would play beautifully over the car stereo. CD players quickly replaced the cassette tape player, but car manufacturers have only recently begun to meet the needs of users who keep all of their tunes on a smart phone or MP3 player. This DIY life hack will show you how to add an auxiliary input to your car's factory radio player.