Gotta be a loose horn wire.
Another good trick to play on ur mates is to put a bunch of cable ties on their radiator fan. Makes em freak out and think their engine is stuffed
That looks preety sick.
There a place in Geelong in Victoria that makes full tub frame chassis lambo countach/f40 etc replicas with full replica interior and uses lexus V8's and sell for around $50,000.