It's always better to give the clue - then people without a copy of the puzzle can help.
20 D. Limp holding up detective missing end part of leg (7
It's a 7-letter synonym for 'limp', limp as in floppy.
13 A. One's said to drive badly while drinking case of vodka with husband. (9)
The answer is obviously longer, because of the theme. You need a three-word phrase for someone reputed to be a bad driver.