Hi!
I'm not sure where else in Malaysia you have visited. But if you are looking for non-touristy sites, why not try a road trip in malaysia. the highways are pretty well connected and you can drive from Kl to Malacca (for heritage/culture/food) or north towards Penang (food, beach) but Penang can have pretty bad traffic jams....

or on your way to Penang you can drop by Ipoh, my hometown for delicious food and to experience a small city in Malaysia. there's not much shopping/nightlife in Ipoh but the food definitely is good. also, if you are interested to visit cave temples (Buddhist) Ipoh is a good place too.

Enjoy!