Outgoing type's former car entered in TT (9)
I believe the answer is:
extrovert
'outgoing type's' is the definition.
(I've seen this before)
'former car entered in tt' is the wordplay.
'former' becomes 'ex'.
'car' becomes 'rover' (former British car manufacturer).
'entered in' indicates putting letters inside.
'rover' put within 'tt' is 'trovert'.
'ex'+'trovert'='EXTROVERT'
(Other definitions for extrovert that I've seen before include "Sociable, outgoing person" , "Outgoing type" , "One who is interested more in outside things than the inner self" , "show-off" , "Person who is more interested in the world than the inner self" .)