The 2005 Dunlop MSA British Touring Car Championship season was the 48th British Touring Car Championship (BTCC) season. As in 2004, there were ten racing weekends at nine different circuits; each round comprising three races, making a thirty round competition in total. Changes for 2005 Teams and drivers After 2004 saw the BTCC boasting its largest number of entries since the height of the Super Touring era in the 1990s, the following season brought a significant decline in interest. Proton and Honda pulled their manufacturer support from the series, with many of the smaller independent teams also deciding against returning. Reigning champions Vauxhall stayed on as one of the two remaining manufacturers, dropping its Astra Coupe after four straight titles with the chassis, and introducing the all new Astra Sport Hatch (again prepared by Triple 8). Reigning champion James Thompson had left the BTCC to contest the World Touring Car Championship with Alfa Romeo, leaving the 2004 runner-up and 2003 champion Yvan Muller to head the team. SEAT Cupra Cup graduate Gavin Smith joined the team after appearing in an Astra Coupe for GA Motorsport at one meeting in 2004, and Colin Turkington moved into Thompson's seat after two promising seasons with the WSR MG squad. Their only manufacturer opposition came from SEAT, expanding their effort to three Super 2000-spec Toledos for their second season. 2001 champion Jason Plato remained as team leader, but Rob Huff departed to join the Chevrolet WTCC campaign. He was replaced by Luke Hines, moving from Vauxhall, with James Pickford taking the third seat as reward for winning the SEAT Cupra Cup in 2004. Team Dynamics took a brave gamble by replacing their Honda Civic Type Rs with a pair of brand new, self-developed Integras. Matt Neal and Dan Eaves remained as drivers. A third car was entered late in the season for Gareth Howell in order to support Neal's title campaign. West Surrey Racing again campaigned the MG ZS as an independent entry after MG Rover withdrew their support at the end of 2003. Rob Collard moved from his self-run Astra Coupe to fill Colin Turkington's seat, but a second driver with sufficient budget could not be found. Arena Motorsport also continued their campaign despite losing manufacturer support, entering a single Honda Civic Type-R for the returning Tom Chilton from the second round onwards. The only other full-time returnees were Synchro Motorsport, with James