Stuck on the parsing for a couple and would appreciate help.....
12a Kind of emission from vehicle - nut needs turning (6) - CARBON ( Kind of emission)
This looks like 'Vehicle' = CAR, but that leaves NOB (Bon 'turning') for 'Nut', which I can't find any justification for (Even in my newly purchased Chambers app!)
19a Headless body a big blow (4) - ONER (A big blow)
I had assumed this was a 5 letter word meaning 'Body' minus it's first letter ('Head'), but can find nothing that matches.