The deal is for the Wednesday test only, as WSR seeks to fill the vacant berth alongside Jake Hill, four-time champion Colin Turkington and Adam Morgan for the 2024 season.
Thompson, the 2022 champion in the Jack Sears Trophy sub-division, has spent the majority of his 130-race BTCC career with Team Hard.
Last season he notched up his best BTCC race result to date with second place at Brands Hatch at the wheel of one of Hard’s Cupra Leons, but was unable to complete the full season because of the team’s mid-campaign requirement for an addition to his agreed budget.
Thompson returned for the final two rounds, and was hailed by three-time champion Matt Neal, who was assisting Team Hard last season, as one of the BTCC’s top six talents.
WSR is in negotiations with drivers to fill the seat vacated by veteran Stephen Jelley, who is returning to the Porsche Carrera Cup GB this season.
The test for Thompson appears to illustrate a desire between the driver and team to spark interest that would allow a race deal to be pushed over the line commercially.
Although all of his BTCC race experience has come from front-wheel-drive cars, Thompson has vast experience of rear-wheel-drive machinery from the coaching and test work he carries out for clients.
“I’m thrilled to test the BMW 330e M Sport at Brands Hatch and I have to thank everybody involved who has worked so hard to create this opportunity,” said 28-year-old Thompson.
“I’ve never had the opportunity to drive a championship-winning car in the BTCC so this will be a first for me, and I really hope it can lead to a race seat for the 2024 season.
“I’m working incredibly hard with my partners to put together a package for this year, but we’re still a bit away from where we need to be in order to make the dream a reality.
“The BTCC is about to enter a new era with a ground-breaking global broadcast deal with ITV Sport and TikTok, which should be a game-changer in what the series can do to promote a commercial sponsor, and there’s honestly nowhere else I’d rather race. I hope this can be a first step towards something really special.”
WSR chief Dick Bennetts added: “Bobby’s one of a group of talented drivers who have come along in the past few seasons, ruffled a few feathers and achieved some very good results when both the machinery and circumstance have allowed it.
“He’s one of the drivers right now who has built an incredibly loyal fanbase and someone who definitely enhances the BTCC just by being there.
“He has plenty of rear-wheel-drive experience, albeit not in a touring car, so this test will focus on getting him comfortable in the BMW and seeing what we can do as a group.
“This is just a test at this stage as we continue to push very hard to make sure our fourth BMW is on the grid this season, but we’re well aware of Bobby’s determination to race and hope we can play a role in making things happen.”