Merredin Trotting Club WA http://www.casinocity.com/au/wa/merredin/merredtc/
Ruakaka Trotting Club , NZ https://www.harnesslink.com/www/Article.cgi?ID=77702
I am not speaking from experience , just found these on the net. The photos of the Ruakaka finishes certainly look like they are on a non-grass surface.