audi a2 1.4 petrol hot starting


6th gear

this is a request by my sister who has a audi a2 1.4 petrol

the probem is and im sure most other a2 owners have come accross this is, when you start the car from cold it is fine, but after a short drive of about 20 min it is a real pain to start, i have read lots on the inernet of people having this problem and lots of things being sugested but no one has said what it really is the cause,

my sister says she thinks it started when her 2 year old son played with all the lights buttons and switches (he had a good time) and left the lights on resalting in the need for a new battery, since then the problem has been there

hope some one can help

many many thanks