I don't feed dd in the car in case she chokes.
I'll never forget my brother giving my nephew a snack in the car - I was driving, my brother was in passenger seat - and he began choking. Terrifying! Stopped immediately, but felt like forever in the moment.
When we have time (we're hopeless in the morning!) she has brekkie at home before we leave but sometimes she eats st nursery instead. All depends on timings. Quick brekkie at home for us is banana and a yoghurt, or one of those fruit & muesli purée pouches with oatcakes. With more time it's cereal, porridge, toast, crumpets or toasted muffins etc.