Trucks

3 clues
Rigs
Big haulers
Highway haulers
Similar answers:
Abackseat
Abstruse
Abstruser
Accostrudely
Acks
Actionjackson
Adirondacks
Adobebricks
Adoctorwholacks
Adspectrum
Aftershucks
Ahotwickskipper
Airlocks
Alanjackson
Alarmclocks
Alarmclucks
Albumtracks
Alecks
Allblacks
Allistrue