I have had this problem with Verizon phones before, it happened when I was playing lacrosse in the rain and the battery got wet. "Car kit" is an error which pops up when there is corrosion on the battery terminals, but it can be fixed, the phone thinks that there is a headset or wireless device attatched to the phone when there isn't. I have the same phone as you but this problem happened on my last Verizon LG phone. Options are to try and dry the phone, remove the battery, power it on and off, or going into the "command prompt" and more or less "hacking" your phone. I tried the last option and it worked. It isnt really "hacking" really just accessing a hidden menu. Try searching "Verizon LG8300 Car Kit Mode" and you should get some helpful answers on some phone forums. Good luck.