in total, this will cost you about $4!....take two bike tubes from walmart...doesnt matter what size....cut a circle around the bottom of the valve stem so you have the valve stem and a little circle below it. cut the air lines on both sides of the rear wheels....plug the air lines inside the underside of the valve stem, snug real tight. you might want to put a dab of super glue on the outside of the air line b4 putting it in the valve stem. .and fill to desired hight with a regular air compressor. My cars air compressor hasnt work for about a year now. and i have tried to fix it but just couldnt get it done. not wanting to spend 360 bucks for a new one, i just thought and thought and finally came up with this. I have had this done for about 3 days now, driving around 100 miles, it hasnt lost air. I disconnected my oem air compressor in the car so it wouldnt turn on wasting battery. Hope someone finds this useful!