The explanation I heard on the Kobe jumping a car spot was that he actually executed a jump which probably would have cleared the car in front of a green screen, and video of the moving car was mapped into the "background". Of course, a lot can be done in composites by playing with frame rates and such, and in a couple years it may be cost effective to produce the same visual entirely with CGI, eliminating the need for Kobe Bryant, an actual car, or even a real pair of Nikes....

With the car moving fast enough, and having a low enough roof, there's probably a decent pool of top atheletes capable of executing the jump depicted, it's much less likely that any of them would be willing to attempt timing the stunt in real time with their lives actually at risk by choice.

With athletes capable of 30+ inch vertical jumps (with their feet elevating higher since coiling the legs moves the feet closer to the CG of the body near the waistline), all that's required is a car that can travel more than its own length in the hang time of the jump and a low enough roof for the jumper's feet to clear. Fortunately, the lower-roofed cars tend to have the higher top speeds, which helps on both counts.

A 30-in. vertical jump involves a hang time of about 0.4 seconds, and 1 mph speed is equivalent to 1.47 ft/sec, so to be jumped at speed, a 15-foot long car would need to be be capable of a speed of 38 mph to travel under the jumper. The roof height on a stock Aston Martin is in the vicinity of 50 inches, meaning you'd need 20 inches of leg retraction to clear it with a 30 inch jump, which is probably possible for someone with a leg length of around 36 inches (I'm not going on google to find out Kobe's inseam, but 36 doesn't strike me as unreasonable for a pro b-ball player). The jump would require the car to approach the jumper already at speed, and would require perfect timing, but the physics/mechanics of the concept do seem plausible.