Over the last few years, sedans have been phased out across the board for GM. The Malibu is gone, the Camaro is gone, and even Cadillac’s smaller cars feel like they’re no longer a priority as the brand leans harder into SUVs and EVs. And yet, GM is still investing in a rear-wheel-drive platform built for the exact type of car it’s been moving away from. Now, a supplier source says GM might be putting a Buick on the same platform as the next Cadillac CT5 and the Camaro. A Buick Built On Cadillac And Camaro Bones Would Be A Big Deal Via Mecum AuctionsAccording to that same source, GM is considering a new Buick sedan for the U.S. market, and it wouldn’t follow the brand’s recent front-wheel-drive formula. Instead, it would share its foundation with the next-generation Cadillac CT5 and the same architecture that previously underpinned the Camaro, which would be quite a major shift for Buick. The sedan is also expected to be built at GM’s Lansing Grand River plant in Michigan, alongside Cadillac models that already use this platform. The brand hasn’t sold a sedan in the U.S. since the Regal ended production in 2020. Since then, the lineup has focused entirely on SUVs like the Encore GX, Envision, and Enclave. Those vehicles cover the volume side of the market, but they don’t really move the brand forward. And unlike those SUVs, a rear-wheel-drive-based sedan would.It changes how the car is engineered and where it fits in GM’s lineup. Buick hasn’t had anything with this kind of foundation in years, and it would immediately sit in a very different space than the rest of its current lineup. It also creates a clear separation from Cadillac while still sharing core engineering. Cadillac continues to lead in performance and positioning, while Buick could occupy a lower price point using the same underlying structure. The Platform GM Never Phased Out Might Be Back CadillacGM’s Alpha architecture has carried some of its most driver-focused cars for years. The Camaro used it, and the Cadillac CT4 and CT5 still do. It’s one of the last rear-wheel-drive platforms GM builds, designed around balance and proportions rather than interior packaging or efficiency.When the Camaro ended production, it seemed like the natural endpoint. Platforms like this don’t usually survive in a lineup dominated by crossovers, but this one did. The CT5 remains in production, and a next-generation version is already in development. That means the platform is being updated and carried forward, not just left in place. Sam Fiorani, vice president of global vehicle forecasting at AutoForecast Solutions, told Automotive News that adding another model would make sense, especially as GM looks to better utilize the Lansing plant. What This Suggests About GM Right Now Bring a TrailerKeeping this platform alive, updating it, and potentially expanding it points to a shift in priorities. If GM had fully moved on from this type of car, there wouldn’t be a next-generation version of this architecture or plans to build more models on it. Platforms like this only continue when there’s a reason to use them.The current sedan market is smaller than it once was, but it hasn’t disappeared. What remains has largely moved upmarket or toward electrification, leaving a less crowded gap in the middle. A Buick positioned on this platform would land directly in that space.It gives GM a way to re-enter the segment without relying entirely on Cadillac and without needing the kind of volume that a car like the Malibu once carried. More importantly, it shows GM hasn’t fully walked away from this type of car.