How long do these things usually last? I had both of mine changed about three years ago and recently the drivers side just busted. I know I should get it changed ASAP but I keep on procrastinating. I would expect them to go longer than three years I'm sure I haven't run over anything to cut them open. Maybe I was given poor quality parts the last time.

How often are you guys changing yours, or how long has yours lasted?

Change it myself or pay someone to do it?