Nobody responded much because of fear of a Tom Cruise reprisal.
Make your own car using an unusual shape. Maybe too square and chunky. Or a large tube. Maybe a half tube roof or something like an old "butterdish" milk tank car. Maybe look at some wargaming vehicles for inspiration.
On the tube idea. Look at my rocket. It is a $1 water bottle, a pantyhose egg shaped container (Leggs), and 25¢ rope grommets with marbles for portholes. Using an egg at each end of a tube and you'd have a unique pill shape.
Other than that, a redecorated aluminum passenger car with a baggage door added? Maybe a dome car with a windowless coopala vs a dome? Or coopala and a dome so you can observe the sky. Do it to an observation car for additional pun!