Nice Yaris, we have one in the family too...fun to drive, but I am not a fan of her on the highway...I find its wheel base, being so short, makes it rather suceptable to big changes in directin from tiny steering imputs...then again I am used to cars like my Subaru Legacy and my former GT car on the highway.
How have you found fuel economy...I find a tank of 87 octane gets me about 500-550km in the city...which seems good, but not great...what have you found?