Argh! Why?Why?

It was like the usual - drive to school and yakking in the car with my girl. Somewhere near Tampines, she told me "mummy, there's something crawling behind you." I looked into the rear mirror and asked "what"
A: There's something crawling on the chair.
A: Going up , going up (points upwards)
M: (panicked) What is it? (dare not lean back on chair)
A: I dunno. (scared look on her face and started to cross her legs on her booster)
M: Where is it now? Is it still there?
A: Yes (scared). It's going up up
M: Is it big or small
A: It's big
M: (lagi more panicked)
A: Yeee......
A: Mummy, it's going to your cardigan
M: (parked the car, quickly opened the door and saw a nymph, opened the other door to let her out) Darn! How to kill cockroach
A maid, washing car next to us, heard me say this and walked over to help me kill and bring out the cockroach. Wah.. she's my heroine.
Why got cockroach? I clean the interior thoroughly once a week. Ai yoh.... I better bring down Dettol later to clean the interior again.