Latest F1 news in brief
Staff changes at Williams, Red Bull
Spyker, Williams, head to Barca for final test
Speed moves closer to 2007 seat
Red Bull implement 'changes' to new car
Karthikeyan returns to A1 series
Bridgestone to supply four tire types in 2007
Kubica urges BMW to improve reliability
Berger questions Speed's 'commitment'