On July 16, in the aching torpid heat of the South Florida summer, Terry Whelper stood at the Avis counter at Miami International Airport and rented a bright red Chrysler LeBaron convertible. He had originally signed up for a Dodge Colt, a sensible low-mileage pact, but his wife had told him go on, be sporty for once in your life. So Terry Whelper got the red LeBaron plus the extra collision coverage, in anticipation of Miami drivers. Into the convertible he inserted the family-his wife Gerri, his son Jason, his daughter Jennifer-and bravely set out for the turnpike. The children, who liked to play car games, began count