A motorist filed a personal injury action against both the driver of the automobile that rear-ended his vehicle and the driver's wife, alleging that the wife, as a co-owner of the automobile, was vicariously liable for the motorist's injuries. The issue became whether Florida Rule of Civil Procedure 1.442 mandates that offers of settlement be differentiated between the defendants, even if a defendant (the wife's) liability is purely vicarious, resulting from the active negligence of her husband. The Court held that a joint proposal for settlement must differentiate between the defendants, even when one defendant's alleged liability is purely vicarious.