The DJR Team Penske star made his return to action after his car-destroying wreck two weeks ago at the Gold Coast 600.

Driving a newly built Mustang after his Bathurst-winning car was a write off in the Surfers Paradise shunt, McLaughlin was third fastest in Friday's sole practice run for the main drivers at the 3.1km track.

Penrite Racing's David Reynolds clocked a lap record of one minute and 07.7779 seconds to top the time sheets with stablemate Anton De Pasquale (1:07.8911) fractionally behind him.

McLaughlin posted a best lap of 1:07.9985 in a strong first competitive drive since his Gold Coast accident.

With a mammoth 463-point lead in the title race over main rival Shane Van Gisbergen, McLaughlin will leave Sandown as the 2019 champion if he finishes Sunday's 500km race with a lead of 300 or more points.

"I just want to execute the best I can and, if I can get a decent result out of it with good points, that's the main thing," the New Zealander said.

"If we lose some points on Shane, we do. If we wrap it up this weekend, we do. For me, it's just business as usual.

"Got to try and use the gap to my advantage in some ways and be like if I've got an opportunity to have a crack like I did last time but we know the consequences of that as well."

Van Gisbergen warmed up for this weekend with the sixth-fastest lap of a session that was marred by showers.

Fellow Red Bull Holden Racing Team star Jamie Whincup fell foul of the conditions when he slid off the wet track midway through the 30-minute session and beached his Commodore in a sand trap.

That sparked a red flag, wiping out Whincup's best lap and leaving him ninth quickest for the day.

Ford's Chaz Mostert, who also wrote off his car at the Gold Coast event, posted the fourth-fastest lap of the session but ended it stuck in a sand trap after he and Scott Pye both drifted off the track.

McLaughlin, having never won the Sandown 500, said the weather loomed as the most-dangerous obstacle to the field.

"We've got a way better package this year, compared to what we were racing with last year, so it makes it a lot easier to drive and stuff," he said of his newly built car.

"I think we've got a really good fight this weekend but it'll just be the weather that everyone's fighting really."

Friday also featured two co-driver sessions.

Van Gisbergen's partner Garth Tander was fastest in opening practice and veteran Craig Lowndes went quickest in the day's final session, which was delayed by 40 minutes after a heavy crash in a support category damaged a track barrier.

The Sandown 500 resumes on Saturday.

Australian Associated Press