After rainy weather in the Southland cancelled the morning session, defending CART FedEx Championship Series champion Juan Montoya topped the time sheets at afternoon practice for Sunday's season-ending Marlboro 500. Montoya's lap time of 30.152 seconds (242.253 mph) on the 2.029-mile superspeedway oval, if repeated during qualifying tomorrow, would eclipse the official CART speed record of 30.316 seconds (240.942 mph) set here in 1997 by Mauricio Gugelmin in his Mercedes-powered Champ Car. The top 16 drivers were within one second of each other, shaping up a hot battle for grid position during Saturday's qualifying session. Tony Kanaan was the quickest of the Mercedes entries, posting a time of 30.765 seconds (237.426 mph) -- eighth fastest on the day. "We tried some new aerodynamic bits today," said Kanaan, who spent time in both his primary and backup Hollywood/Mo Nunn Mercedes race cars during the 90-minute session. "We also scrubbed some tires for the race, in case it rains tomorrow. We'll evaluate our results, and figure out what we really want for the race. Overall, it was a very productive day." Gugelmin lapped the race track in 31.052 seconds (235.231 mph) for 14th place while teammate Mark Blundell, who won this race in 1997, was 20th in his PacWest Motorola Mercedes with a time of 31.486 seconds/231.989 mph. Herdez/Bettenhausen Motorsports pilot Michel Jourdain Jr. was 24th (31.916 seconds/228.863 mph), while Luiz Garcia Jr. was 27th (33.155 seconds/220.311 mph). Qualifying begins Saturday at 10:45 a.m. PT. The green flag for the Marlboro 500 waves at 11:30 a.m. PT Sunday (live, ESPN).