One of the most common questions we hear from Toyota GR Yaris owners is: “What’s the biggest bucket seat I can install without running into fitment issues?” At first glance, this might seem like a straightforward query, but when you take a closer look at the GR Yaris interior, things get a bit more complicated. This compact rally-bred hatchback is packed with performance, but it comes with a tightly proportioned cockpit that limits how much space you have to work with, especially when it comes to aftermarket racing seats.

Here at GSM Performance, we’ve spent time testing seat fitment both in our showroom and through real-world customer installations. Thanks to that hands-on experience, we can confidently say that the sweet spot for bucket seat sizing inside a GR Yaris falls under a maximum shoulder width of 580mm and a base width of 520mm. These dimensions give you just enough room to install a high-performance seat without it fouling on the doors, centre console, or interior trim. In this blog, we’ll break down what that really means, which seats we’ve confirmed will fit, and highlight the best motorsport-ready options that strike the right balance between size and comfort—while meeting FIA safety standards.