Get there early as there is loads to see.
Don't bother with the house with small children - we didn't have time anyway.
Make sure they go to the loo before starting the safari bit in the car - DS1 had to wee in a fruit shoot bottle in the lion enclosure. He wondered why he couldn't get out to go behind a bush.
Pets Corner - you are more likely to see the 'famous' keepers in there (from Animal Park).
We didn't see anybody's car get destroyed tbh. One ran over our car but I think the trick is not to stop in the monkey enclosure.
If you don't have a CD player in your car, take one for the commentary CD.
Boat trip was my favourite bit but the queue was horrendous.