Add spaces: Analertlightonthedashboardremindsyoutobuckleupifthebeltisnoton.

Answer: An alert light on the dashboard reminds you to buckle up if the belt is not on.

Add spaces: -Wecanhappilysupplyanotherbrand.

Answer: - We can happily supply another brand.

Add spaces: Therivertroutwithitsgoldencoloursanddarkredspotsisoneofourmostbeautifulfish.

Answer:
The river trout with its golden colours and dark red spots is one of our most beautiful fish.