How are race cars made? Well, when a BMW M4 GT4 and an Aston Martin Vantage GT4 love each other very much, the BMW mounts the Aston and… Ok, kidding aside, it was pretty remarkable to watch an M4 GT4 actually leapfrog an Aston Martin during last weekend’s IMSA Michelin Pilot Challenge Race in Detroit.

Coming into a turn, the Turner Motorsports BMW M4 GT4 driver Robert Megennis seemed as if he was trying to take the inside line but was carrying far too much speed. It’s unclear how exactly this happened, whether the M4’s tires were too cold or its brakes faded but, either way, Megennis went into the turn too hot and he drove into the driver’s side rear quarter panel of Rory Van Der Steur’s Aston Martin Vantage GT4. Once Megennis his Van Der Steur, the M4 GT4 climbed on top of the Aston, forcing the Aston to slide into the barrier with the M4 GT4 on its roof. Once they hit, the M4 GT4 slide off the Aston, back onto its wheels, and was able to actually drive away.

Neither car was able to continue, and both had to retire from the race, which isn’t surprising. However, they suffered less visual damage than you might imagine, judging by the description of the crash.

The BMW M4 GT4 is an impressive race car and is mechanically extremely similar to the M4 road car. It still uses the same 3.0-liter twin-turbo inline-six, which can make up to 550 horsepower depending on the specific racing regulations. However, it’s paired with a seven-speed ZF automatic, rather than the road car’s eight speed. It doesn’t need the extra tall eighth gear, so shedding that bit of weight is helpful. The GT4 version is also significantly lighter than the road car, thanks to extensive uses of lightweight composites. Interestingly, though, the M4 GT4 uses quite a bit of natural fiber composite parts, rather than traditional carbon fiber. Its roof is the only major carbon fiber component, while almost all other composites are made from natural fibers.

This isn’t the first time cars have ever leapfrogged each other in racing but it’s always jarring to see. Watching a car just hop on top of another at that sort of speed is wild and it must be terrifying for the drivers on board both cars. Thankfully, neither driver was injured, only the cars took any sort of damage.