Citroen's C4 Cactus is more than just another compact car. It's a manifesto on wheels for the brand's move down-market as parent PSA Peugeot Citroen struggles to return to profit. The car, lent to reporters for test drives this week as European sales get underway, sports slightly wacky features including bench seats and rugged-looking squishy plastic "Airbump" exterior door panels developed by BASF.