tailgating

Noun

 * 1) The act of driving dangerously close behind another vehicle.
 * 2) A tailgate party social event held on and around the open tailgate of a vehicle

Usage notes
Sense 1 is not to be confused with drafting, though the context of both words is similar and related.

Translations

 * Dutch:
 * German: zu dichtes Auffahren, Drängeln
 * Vietnamese: bám sát đuôi