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.