I've placed speakers in two different places in my trucks. In my day cab I used a smaller speaker and place it in the front grill above the servo's, and in the sleeper of my ford-max.
in both cases I did not use the speaker box that Tamiya provides with the MFU kit. It saved me a lot of space, though its not as loud. Believe me its plenty loud without the box that's provided. So don't be afraid not to use it.
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