Amy has the car. If she wants to put herself out to pick up the friends then its for no charge. If the friends want to save money and put pressure on her to pick them up and she doesnt want to, they should not push it. If she doesnt offer they shouldnt ask.
If this is causing them some consternation, then how will they share a holiday together. If Amy is the one thinking about it, then she should probably offer. If they have luggage she probably cant fit it all in the car anyway.
Every shot I hit is in the comfort zone. My opponent's comfort zone.