Thanks to Bret Indralee for the inspiration.
The Creature that Lives in the Trunk is one of the most successful Horrors at adapting to it's new surroundings during the invasion. On Gaea, The Creature was limited to steamers and the occasional valise, spending most of it's time locked in attics and cargo holds, able only to frighten porters with any regularity. But on Core Earth, The Creature has been able to find a home for itself very close to the heart of each and every modern man - in their cars!
The Creature takes up residence, where else, in the trunk of the car, most often dislodging the spare tire to make room. At first the unsuspecting motorist notices nothing, except perhaps a tendency not to be able to find things they were sure they had left in the trunk (like the spare!), and perhaps an odd smell or two. But as The Creature makes itself more at home, the problems begin to build. Strange thumps can be heard on tight corners. Breaks squeal at horrible times, even though they seem to work. The muffler appears to lose all function, as well as the catlytic converter. The radio begins to skip stations, not entirely at random. Sparkplugs no longer seem to fire in the proper sequence. The windshield wipers develop holes, and the fluid tank is always empty. Even the paint job loses it's factory finish, and the underbody coating does even less than before.
Of course, all of these problems disappear as soon someone else is asked to look at the car. The engine runs like a charm, the brakes are silent and firm, the air conditioner perfect. Until they drive away, and the noises begin to build once again. The Creature, so long locked in an immobile trunk, revels in it's newfound power, and plays with it's victim with an instinctual skill. At first the problems are minor, prompting the owner to merely care for the car even more. Then they worsen, but only at a rate that the owner is able to keep up with them, both in the time and money needed to have them checked. Only when the owner is right at the edge, already sure that their mechanic and their friends are all insane, does The Creature drive them over with an unending stream of problems, each worse than the last, but even then spread out, one at a time, always promising that this will be the last, and then the car will run perfect. But no matter what the owner tries - theft, assault, sacrifice of friends, family, mechanics, or pedestrians - the car finally breaks down (most often in the middle of a high speed chase), and The Creature moves on.
But with all the cars in the world, The Creature never had it so good...