CALIFORNIA PROPERTY DAMAGE SETTLEMENT OFFER: Should I accept the insurance Claims Adjuster's quick Settlement Offer regarding my vehicle's property damage?

Sometimes an insurance adjuster will inspect your car's damage and then use a program on his/her mobile lap top to calculate how much the insurance company believes it will cost to get your car fixed.  They will issue a check right there on the spot - it is extremely important that your agreement to settle quickly also means that if any reputable body shop finds it cannot repair the vehicle for the estimate provided to you on the spot, that a "supplemental" inspection can take place for a "supplemental" payment or check.  This is important, as you do not want to be tricked into settling your property damage for less than it is actually worth to repair.