Few are noticing the progress being made by Vauxhall - Groupe PSA's ex-GM unit that is UK market only sister brand to Opel. In March it moved closer to Volkswagen and pulled away from fourth place Mercedes with the strongest growth of any top-ten brand. The main reason is a renaissance for the Corsa, yet the Insignia is also doing surprisingly, sales pushing past the 5,000 units mark in Q1.