Honda recent models rust under bonnet & subframe

Any other recent HONDA owners with this problem? Or if you are not sure, check your car out in case!

Just discovered my Honda HRV 2016 model, still under warranty, has developed under bonnet rust on many painted steel edges (e.g. drain holes, bracket welded edges etc.) and on front edge of under-engine sub-frame. Made in Thailand. Paint looks thin. Body panels OK. Dealer has reported “NORMAL IN COASTAL CONDITIONS”. Dealer is near the coast but car is fully garaged 20km from coast & mainly driven away from coast.

I am waiting on Honda Australia to decide if they will cover it. This is my 5th Honda & the first one with this problem. Googled problem & other Honda models also have same issue.

This Honda rust compares very unfavourably to a 19 year old Corolla (owned from new) with 300,000 km garaged, under bonnet of which is absolutely perfect. Plus, Corolla owner used to work 5 days a week on coast!