Got there in the end, but perhaps a little trickier this week (not least after spending a long time trying to relate 4d to 21a...)
Can anyone help me with the parsing of 15d, I believe it breaks down to 3, 2, 1; but can't relate the 2,1 to "in pole position"...
I also can't figure out which words we are scratching the backsides off in 19a!!
Thank you forum!