I was surprised I had to go out of my way to get it actually. I got the human stopwatch trophy (which I thought would have been harder to get...) during the karting special events, and I'd had my fair share of close finishes over my racing career up until the point where I decided to "Engineer "Within One Hundredth"". But they must've been all over 0.01 obviously. I'm pretty sure I recall some 0.060 and 0.030 finishes... I always prioritized winning over trophying.
I got mine doing the nascar special event.