AS a first attempt to muscle in on the hallowed turf occupied by BMW's M3 for more than 20 years, the IS F should be given some slack. Or should it, seeing as this Japanese upstart matches the Germans on performance and packaging while significantly undercutting them on price? Sure, there are areas where more work is needed (ride quality being foremost), but Lexus need not make any excuses for a four-door sedan as ballistic as this. In fact, we ought to be extremely grateful indeed that it even exists.