Surprised Targets may not Evade, and are Very Easy to hit (+30 to BS test).
Flamers and other Spray weapons do not test BS, the Target rolls Ag. to avoid being hit. This test is in addition to any Reaction the Target may attempt to avoid the area of effect alltogether.
So how do we handle surprise attacks with Flamers?
Sure, they may not dodge, but is it still just a Challenging Agility test to avoid being hit? Should they get a penalty? Should they be allowed to test at all? How about the test to avoid catching fire?