Few pairings in motorsport history carry the poetic weight of Ayrton Senna and the Honda NSX. The legendary three-time Formula 1 World Champion famously helped Honda stiffen the chassis of their revolutionary sports car by 50 percent during development testing.However, his connection to the model went far beyond test tracks. Now, an incredible piece of racing lore is crossing the auction block: Senna's personally allocated 1991 Honda NSX is heading to RM Sotheby's London Auction this October.Credit: Ken Saito @2026 Courtesy of RM Sotheby'sAdvertisementAdvertisementThe vehicle in question is chassis number JHMNA11500T000233, an exquisite example combining Formula Red paintwork with a black roof and a black leather interior. Rather than sitting in a museum, this specific NSX was supplied directly by Honda to Senna for his personal use in Portugal.Honda Automobil de Portugal imported the sports car and officially registered it on March 22, 1991, outfitting it with the license plate "SX-25-59".The car was permanently stored in Lisbon and was made readily available to the F1 champion whenever he visited the country, where he owned a property in the exclusive Quinta do Lago resort. Senna famously drove this exact car to the 1991 Portuguese Grand Prix at Estoril, a race where he qualified third and ultimately finished second on the podium.Credit: Ken Saito @2026 Courtesy of RM Sotheby'sA Pop Culture IconBeyond its grand prix pedigree, this Formula Red NSX is widely recognized due to its prominent appearances in motorsport media. The vehicle was featured in the acclaimed 1992 documentary "Ayrton Senna: Racing Is In My Blood," where footage captured Senna aggressively spinning its rear tyres for the camera.AdvertisementAdvertisementHowever, its most iconic appearance came in a series of candid, widely circulated photographs showing Senna washing the car in a driveway with a simple garden hose. Those specific images cemented this red chassis as one of the most recognizable road cars associated with the late Formula 1 champion.Collectors and enthusiasts looking to acquire this piece of automotive royalty will need deep pockets. The car will be auctioned as Lot r0002 at RM Sotheby's The London Auction 2026, which takes place on October 31, 2026, at The Peninsula London.RM Sotheby's has placed a pre-sale estimate of £500,000 to £800,000 GBP on the vehicle, which roughly translates to between $700,000 and $1.1 million. Given the skyrocketing demand for pristine golden-era JDM cars and the unparalleled historical provenance attached to Ayrton Senna, the final hammer price could easily exceed those expectations.