Taxi dillema... PLEASE HELP!!!?

I have just qualified as a taxi driver and am looking forward to my first shift next Tuesday. However, there are a few things that im worrying about. I have a stomach problem and occionally get very bad gas. Should I apologise in advance and ask the customer to open the window while I release my gas, or just do it and pretend it never happened? Secondly, I have a certain fondness for death metal rock music and find I cannot concentrate on driving without playing my fave song ('DIE WORLD DIEEE' by 'I LOVE MACRES')... Should I continue to play my music at a deafening level and just ignore the wishes of my customers... or should I risk permanent paralysis and death by turning the music off? Please Please Help!!