Hey here's what I did hope it helps and provides clarity
Having already done 50 races 2 days in a row and receiving nothing, I created a third profile,
I then used my design for 55 races also liking it on the third profile, my design included paint and vinyl/decals
I then went to my second profile and did 50 races with the same design and liked it, I then changed car and design did 30 races, liked the design
This got me 19k cr and the first two achievements
The next day I used a new design 50 uses and a like on both profiles, then a third design 20 races and a like
I received another 19k and the final achievement
I'm not sure if the likes are relevant but I thought it safe to get those too and mention them