Last year, Scott McLaughlin clinched a third straight drivers' title, with the Kiwi carrying the iconic #17 numberplate to each of his successes.
The 2020 championship was the eighth for the #17 numberplate. Only one number in history has won more, being the #1.
The #1 has been carried to a record 14 championships in Australian Touring Car Championship/Supercars history.
Four of Jamie Whincup's record seven titles came with the #1 on the window.
The #1 has won 188 of the category's 1055 races since its 1960 inception; however, the 2018 Sandown 500 was the last win for the number.
Dick Johnson's five titles all came with the #17 on the door, with McLaughlin taking the tally to eight with his hat-trick of crowns.
In all, 13 different numbers have won multiple titles, with nine different numbers winning one title.
The last win for the #1 was with Whincup in 2014, before Mark Winterbottom claimed the third win for the #5 in 2015.
Winterbottom's breakthrough came 51 years after Ian Geoghegan carried the #5 to its first title at Lakeside aboard his Ford Cortina GT.
Behind the #1 and #17 is the #2, which has delivered five titles.
Mark Skaife carried the #2 to three titles across two different manufacturers, with Nissan (1992) and Holden (1994 and 2000)
The #1 will be absent for a third season, with Whincup last carrying the number in 2018 following his title triumph the year prior.
Norm Beechey campaigned the #4 to the 1970 title, but also ran the #24 at the Lakeside round.
A year later, Bob Jane steered the #7 to victory, but also carried the #6 during the season.
There will be 12 numbers on the 2021 Repco Supercars Championship grid that have previously won titles; #2, #3, #4, #5, #7, #8, #9, #17, #18, #34, #88 and #97.
Cars will hit the track on Friday for opening practice of the Repco Mt Panorama 500. Tickets are on sale now.
This weekend’s event will be broadcast live on Foxtel and the Seven Network, and will be streamed on Kayo. Check out the full TV schedule here.
Numbers which have won ATCC/Supercars titles