Sometimes getting someone to fix your car as a favor just isn't worth it, says a new campaign by Mother London for UK automotive retailer Halfords (which is offering services such as fitting wiper blades, bulbs and batteries in the parking lot). Because they're going to want something in return. Three spots straplined "#Worst Favour Ever" bring to life some creepy, annoying or just plain painful scenarios in which a favor turns out to be a curse in disguise. The brand is also encouraging consumers to tweet their "Worst Favour Ever" at its website in order to win vouchers and be entered for a prize draw.