Have started potty training DD2 (just 2yrs old) Has been doing really well at home for about a month. For the last three days I have taken her out without a nappy on and she's been fine (except a tiny weeny wee on sainsburys floor. At nursery today she just had a tiny accident on her way to potty, but is doing really well. Have to drive down to PIL tomorrow on my own, it's about a two hour journey on M25 (so could be longer). Don't know wether to put her in a nappy, or just put a mat under her in her car seat and chance it. What would you do?