Mix vinegar and sugar and heat in a non-stick pan, stirring, till sugar dissolves. Pour into a bowl. Cut carrot and raw mango into thin strips.
Deseed and cut cucumber into thin strips. Add all these to the vinegar mixture in the bowl and mix well. Let it stand, preferably overnight.
Heat some water in a non-stick pan, but do not boil.
Spread a wet cloth on the work top. Soak rice paper in warm water till they become transparent, take them out of the water and spread them out on the wet cloth.
Place some rice noodles in the centre, followed by pickled vegetables, sweet basil leaves, a few fresh coriander sprigs, few mint leaves and roll tightly but gently, folding the sides as you roll.
Make remaining rolls similarly and place them on a plate. Heat red chilli flakes with honey in a non-stick pan and let this come to a boil. Pour into a bowl, add 1 tsp vinegar from the pickled vegetables and mix.
Cut the rice rolls into half and arrange them on a serving platter. Drizzle the sweet chilli sauce over them, garnish with a few sweet basil leaves and serve immediately.