As title really. Had the carpet out to clean it and the seats and the floor is a bit grubby. It is 20 odd years old after all

Cleaned it up best i can but i want to paint it while everything is out. Don't want a top quality spray job or anything, just wanna hand paint it and have it looking a lot better. Anyone used or can recommend the best stuff to use ? Been told to use white hammerite as it's not a bad match colour wise but open to suggestions. cheeRS, Dry.