French outfit RC has now registered two of the ex-factory cars for the 2017 season, one of which will be driven by Muller's nephew Yann Ehrlacher.
The 20-year-old drove for his uncle's outfit in the European Le Mans Series last year, having previously won two domestic championships in his native France, and has already tested the Vesta for RC, which is based at the Magny-Cours circuit.
The team is expected to announce its second driver in the coming weeks.
"This is such an amazing opportunity for me and I really can't believe it's happening," said Ehrlacher.
"I've been really impressed with the car during testing and the team is working really hard too."
WTCC-2 DROPPED FOR 2017
WTCC organisers have dropped plans to introduce a second, WTCC-2 tier for the 2017 season.
After Lada's withdrawal prompted fears about grid numbers for the 2017 season, plans were ratified at the previous World Motor Sport Council meeting in November for a second class of TCN2 cars, based largely around TCR regulations, to be allowed to race in the championship.
But with 16 TC1 cars registered for the full 2017 campaign, those plans have been abandoned - and Thursday's WMSC meeting confirmed the class would not go ahead.
"The proposed WTCC-2 category announced at the conclusion of the World Motorsport Council of November 30 2016 has been deleted for the 2017 season," read a statement from the FIA.
"This has been done to allow the Touring Car Commission and the promoter to focus entirely on the main category [TC1] in 2017."
The WMSC meeting also confirmed the date of the Argentinian round at Termas de Rio Hondo would be brought forward by three weeks to the July 16 weekend, and that as anticipated the Chinese round will move from Shanghai to the Ningbo International Circuit.
CONFIRMED 2017 WTCC LINE-UP SO FAR
Honda: Tiago Monteiro, Norbert Michelisz, Ryo Michigami Volvo: Thed Bjork, Nick Catsburg, Nestor Girolami Sebastien Loeb Racing Citroen: Mehdi Bennani, Tom Chilton, John Filippi Munnich Motorsport Citroen: Rob Huff ROAL Motorsport Chevrolet: Tom Coronel Zengo Motorsport Honda: Aurelien Panis RC Motorsport Lada: Yann Ehrlacher
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The 2012 World Touring Car champion says he never had the money to race cars. Yet 2015 is his 11th season in the WTCC. He talks STUART CODLING through his journey from motorsport fan to paid professional - for little more than £100,000