Forza Horizon 3

First get the free 2016 Nissan Titan Warrior Concept car and drive to the point on the screenshot:


The snowman is in front of the house south of the location.

You can use rewind to destroy the same snowman 10 times. Best time to rewind is after the Snowman skill is shown. If not, also rewind after a second from crashing, as the skill may not always show.
After rewind wait a few seconds before crashing into it for the skillpoints to be counted again.

Edit:
It is best to snap the achievement app and use rewind 2 or 3 times after crashing with snowman to find the best time to do it.
It seems that the Snowman skill is the requirement for the achievement, and the progress is only increased after it is shown.

Thank you ALI900 and Renattooo

Edit2:
I've recorded a clip showing the way of getting the Snowman skill to count for the achievement:

I don't know why it counted twice at the beginning

Car: 2016 Nissan Titan Warrior Concept (Free at the Autoshow)

Get in this car and fast travel to the small village near the bottom right of the map. Once you get here you should find snowmen in front of the houses on the paved roads. You can even use the rewind feature to destroy the same snowman 10 times. Or find a bunch and then revisit this location later on. You can even create a snowman bucket list blueprint if you prefer!

You'll find snowmen in the small town near the festival, there are more than enough to do this in one go.