Speedcafe understands Slade has now locked in his move amid a co-driver market that has unfolded rapidly since October’s Bathurst 1000.
Slade loomed as one of the big signings of the co-driver silly season since his retirement from full-time driving was confirmed in late September.
The 39-year-old had initially been in the mix for seats at Dick Johnson Racing and Triple Eight.
The DJR door closed when the team elected to sign Brodie Kostecki’s 2024 Bathurst-winning co-driver Todd Hazelwood.
Triple Eight is also full, with Scott Pye continuing to co-drive having missed out on a full-time return, and Jamie Whincup having elected to drive on.
Slade’s decision is understood to have come down to a choice between Percat and MSR or Team 18 and its new signing Anton De Pasquale.
The MSR deal will reconnect Slade with fellow South Australian Percat, the Stone family and patron James Rosenberg.
The drivers were teammates at Walkinshaw Racing in 2014 and at Brad Jones Racing from 2017-19.
Slade had earlier driven for Stone Brothers Racing – the legendary squad co-owned by Matt Stone’s father, Jimmy – between 2010 and ‘12.
Rosenberg, meanwhile, helped Slade through much of his career and is currently involved at MSR through a personal sponsorship of Percat.
Like many of the recent co-driver deals, the Slade/MSR union is not expected to be announced until after this weekend’s season-ending VAILO Adelaide 500.
Slade’s focus is firmly on farewelling full-time driving with his current team PremiAir Racing.
“I started my full-time Supercars career [here] in 2009 and to finish it off a few years later in the same place is nice,” he said ahead of opening practice on Thursday.
“Adelaide is home for me, I still have family here, so it’s nice to share that final full-time weekend with them.
“Personally, the approach is no different. I haven’t really thought about it in any different way, I just want to have the best results possible.”
Slade is relatively unemotional about retirement from full-time Supercars driving. He’d sat out the 2020 season before two-year stints at the Blanchard Racing Team and now PremiAir.
“It’s what I’ve done my whole life. I started racing go-karts when I was nine and I’m 39 now, it’s my 16th year in Supercars,” he said.
“I’m sure it’ll feel a little bit different once I’ve been out of it for a little bit, but I guess I’ve been in this situation once before when I co-drove in 2020.
“I am happy with where I’m at and excited for what’s next. It’d be nice to finish it off in a decent way, hopefully a lot better than what the last couple of races have been.”