What kind of system should I put in my mini cooper?

[hannah]

I have a mini cooper and i want to put a system in it. I already have a non-stock radio, my car came with harmon kardon speakers so i don't want to change that, i just want to add more bass or more "bump" to me car. i don't want it to take up much room at all either since i do have a tiny car. PLEASE HELP!!

 

[Richard A]

put in a amp

 

[D R]

go to best buy and ask them they can match it to your price range and size and price.