Would help if the op could post a recording of the sound as, from what he described, I don't think any of the responses are correct. Except maybe the one who said it may be a frog as we have a frog here that sounds like that.
I have both a fortuna legender an a yaris cross ( for the misses). Can't find a bad thing to say about either. Despite that some are derogatory against the fortuna they don't realise that it no longer uses the hilux train but has its own unique chassis. It also has all the latest features available giving the extra room for trips with family and friends. The cross is an incredible car but i have to sneak a drive. Misses very possessive. Would recommend either depending on your requirements.
Thanks for the clarification. Yes we did get the Yaris Cross. The misses won't let me drive it. It truly is a beautiful vehicle. I didn't see the Corolla option when we got this but I know it available in Australia.