Thats quite a short warm up. Although these things are quite individual, what works for some doesnt work for others.
I do about 20 minutes on the track (motorpaced) then after that come off and get on the rollers just to spin the legs and keep things moving but with a few high cadence efforts mixed in too - i do this up to the racers are called to line up. Where i race first is usually a 10 lap scratch so you've got to be good to go from the gun and that generally means rolling to the start already dripping in sweat!
I dont do any stretching beforehand, but do lots afterwards.