BMW Putting E60 M5's V-10, 6MT Into a 1st-Gen X5Heritage Images - Getty ImagesNow that the automotive world is decades into its high-performance SUV era, the first BMW X5 has aged particularly well. Still, when people think about classic BMWs of the 2000s, their minds are more likely to wander to performance icons like the "Clownshoe" Z3 or the E60 M5's screeching V-10. Ronnie Fieg, founder of of lifestyle brand and regular BMW collaboration partner Kith, appreciates both the X5 and its higher-performance relatives; that's why he had BMW install an S85 V-10 and a manual transmission in an E53-generation X5.While the E39 M5's S62 V-8 is actually the contemporary to the E53 X5, Fieg's latest collaboration instead pairs the SUV with what might be the wildest engine to land in any series production sedan. And not only is it paired with a six-speed stick—the right choice for any enthusiast looking at an S85-powered car—Fieg says on Instagram that the manual transmission feeds directly into the car's original all-wheel drive system.yet as crazy as this particular build is, it is far from the strangest thing BMW has ever built out of an E53 X5 and an existing engine in its portfolio. That honor belongs to the X5 Le Mans, an X5 powered by the P75 V-12 from the Le Mans-winning V12 LMR. BMW built that car all the way back in 2000, when the E53 and the V12 LMR were still new models, and it also had a six-speed manual transmission.The BMW X5 Le Mans.BMWThe newer of the two outrageous X5 engine swaps is set to debut at BMW's Pebble Beach activation this weekend, as part of a new "Kith for BMW" partnership. Fieg also mentions a Kith-branded 2027 BMW X5 set to be shown off at the same event, plus an E9 3.0 CSL and E24 6-Series complete in Inka Orange also shown off in a Wednesday Instagram post.You Might Also LikeIf You Can Only Own One Car, Make It One of TheseThese Are the Most Popular Cars by State