How do I get the nerds to the scrapyard without them being scared off?

The obvious solution, driving them to the junkyard carpark, doesn't seem to work, because Kendra keeps telling them to wait behind when she goes for a drive! How can I get her to take them in the car with her?

If that doesn't work, I'll have to disguise them so the jock doesn't recognise them. There are 3 nerds and 3 unused costumes (tiger, mouse, bear) left in the auditorium. Trouble is, the game keeps telling me, "You don't think you need another costume." Wrong! I **DO** think I need it to disguise the nerds! So how can I convince the game that it isn't psychic and I'm the only one who really knows what I'm thinking?

Failing that, can I at least get the dragon costume back off Silus and Venna and give it to the nerds? (This is obviously going to be a last resort approach, since it will mean S&V won't have a disguise any more.)

That's three possible approaches to the problem, how can I get any of them to work? It's driving me crazy!