building type kit for 8 year old- any ideas?

[fruitcorner]

My DS love making things and has loads of lego, I would like to buy him some extra things so he can make remote control models or models with power functions but not necessarily a proper kit just some extras that he could use to adapt his lego /knex and use as he wants rather than to build a specific model -IYKWIM . I have looked at the lego power functions kit and I think Knex do some power functions too - does anyone have any ideas?

[fruitcorner]

Bump!

[shineypenny]

Hot Wires is brilliant.

[Tiggles]

Knex have a solar powered motor that you can buy on ebay (search for "solar knex" and there are a few). My son loved that addition.

[fruitcorner]

Great thank you, I will look at those ideas