Question

Why the inside of a vehicle with a light coloured surface is a little cooler than that of a dark,rough,textured one?

Answer 1

A light colored surface reflects most of sun light incident on it. So the hot sun rays fall on the surface and get reflected away. Only a small part of the sun light, that has fallen on the    car is absorbed. The absorbed amount of light heats the surface. The inside of the car gets heated from the roof. If roof absorbs less amount of heat, then it stays cooler.
Dark colored surfaces absorb more light. and so they get heated faster.

Answer 2

as we all wear light coloured cloth in summer to be cool , the inside of a vehicle is also light coloured to be cool . the engine of vehicle is present inside the vehicle it itself become very hot and in addition if dark colour would be there then it would blast due to warm atmosphere . so inside of vehicle is painted light coloured to maintain the tempreture . the same logic is applied for the inside of vehicle not being rough , textured , ect.