Characters travelling around in double decker? I'll give you that! (4)
I believe the answer is:
cede
'give you that' is the definition.
'cede' can be an answer for 'give' (thesaurus). I am not sure about the rest of the definition.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for cede that I've seen before include "Give up rights or possession" , "Surrender or yield" , "Yield or give up to another" , "Give up (territory)" , "Give up (eg, power)" .)