Possible Clues:

• Promotion
• Promotion in rank
• Vehicle covered by bill sticker — that's promotion!
• Notice vehicle will join together with forward movement
• Promotion from publicists not ultimately enthralling Packard
• Notice sticker on vehicle making headway
• Onward motion
• Process of developing sealant for putting underneath commercial vehicle
• In modern times, those in front make fast progress
• Bond, going after a vehicle carrying diamonds, is getting on