Two bad drivers regularly ignored crawlers (7)
I believe the answer is:
toadies
'crawlers' is the definition.
('toady' can be a synonym of 'crawler')
'two bad drivers regularly ignored' is the wordplay.
'regularly ignored' indicates alternate letters.
'two'+'bad'+'drivers'='twobaddrivers'
The alternate letters of 'twobaddrivers' are 'TOADIES'.
(Other definitions for toadies that I've seen before include "Slimy amphibious types" , "Flatterers, sycophants" , "Yes-men" , "Bootlickers" , "People who flatter and behave obsequiously" .)