UPDATE
Looks like an update to the game has changed the order of the events in anniversary mode so this guide doesnt apply anymore.
This can only be done in the anniversary mode if doesnt count the events in career. Seems to unlock after only 10 events also.
For some reason the second event counts as 5 so the tracker jumps straight to 50% then continues up to 91% with each event you do.
Once at 91% you should be at the celica on kenya which wont track so youll have to do one more event being the female audi team at sanremo which will then unlock the achievement after only 10 events.
I cant really give any tips as it depends on the driver but id imagine some people are stuck on the 3rd event, audi at monte carlo.
I was stuck on this one for a bit getting 30secs over all the time.
I was trying to be too fast and kept hitting rocks and snow banks. Slow down a bit, take it easy then you should start crashing less. I ended up around 10secs under after i slowed down and focused on not touching the walls.