As any college student can attest, It's spring break time. You know, that annual rite in which hedonistic rich kids flee campus for beach resorts in Florida, Texas, and Mexico to let off steam, work on their suntans, and imbibe vast quantities of adult beverages ... even if they're not yet of legal age. But in the midst of all the revelry comes word of an incident that threatens to undermine that carefully cultivated image of immature behavior. As Charlotte Papenbrock tells it, she'd returned to her parked car on South Padre Island, Texas, to find the rear windshield smashed to pieces - perhaps from some errantly thrown object such as a football. Assuming a vacationing student was responsible, she said she was "upset ... [because] there was glass everywhere." The retiree from Blue Springs, Mo., who spends her winters in the warm climes of the southern Lone Star State, telephoned police to report her discovery. But then she noticed something else among all the shards on the back seat - a wad of bills that she hadn't left there. It amounted to $200 and was accompanied by an unsigned note: "Here you go. I'm sorry." The cash went to repair the damage, and an appreciative Charlotte said she wanted to pass along a message: "Tell those kids I'm very proud [of them], and their mothers would be, too."