I'm at 32 now, golded everything before. Still on a working week as well so I only played a bit for two evenings.
I think 31 so far was the hardest for me (if I'm not mistaken), it was the "speed out of a corner" at the last corners before the long Nordschleife straight in the Ferrari 458 Gr.4. But after a dozen tries or so I got it. Same for the Aston Martin Gr.4 at Brands Hatch corner 4, that has always been a corner I knew I didn't take so effective, took a couple of tries but I was glad I got it.
Will complete the others over the weekend. In the end it's not hard at all, even if you struggle with one, just keep trying and trying and as you get used to the challenge ahead you will eventually get gold.
Been doing some mission challenges and track challenges along the way as well, to be honest I like those more as they include more full races.