1) Are RED cars more expensive to insure?
No.
2) Are Sedans cheaper to insure than Coupes?
Generally, yes.
3) If you fail to notify your carrier that your teenager is now licensed, and they have an accident-
are you covered?
Due to insurance companies good faith, probably, but I wouldn't chance it. Notify them of
any drivers.
4) If you borrow your friend's care and have an accident-which insurance company pays?
Generally, insurance follows the vehicle 1st, the driver second.
5) If you have regular use of your friends car-does that change anything?
Yes, due to the regular use rule, there may not be coverage if you fail to notify the vehicle
carrier that you are a regular use driver.