I'm not an expert but my sister has epilepsy, two types affecting two parts of the brain.
One causes 'full' seizures and the other absences, before diagnosis following a 'full' seizure at 7 she only had absences.
These presented as a
'daydreamy' state,
forgetting things eg going upstairs to get something and just coming back down again,
slurry speech and loss of words,
these usually occured in the morning but also like your lo on car journeys we later found out that objects passing by had similar effect to strobe lighting which she is sensitive to.
My sis was treated with meds and seizure free until around 18 when college stress became too much and meds changed due to epilim causing problems with fertility in girls. She's 25 now and has still unfortunately not been successful with meds especially mixed with a very hedonistic lifestyle! She has had lots of tests and scans etc and its only fairly recently(past 6-7 years) that we've had any explanations as to the cause and nature of the epilepsy, mostly due to how well controlled it was in childhood.
I agree with the diary my sis still does this, I hope this helps. Good luck