The one thing most Slingshot owners will agree on is that it's quite loud in the cabin while driving. If you'd like to really hear your music while driving at freeway speeds.. these inward facing arm rest speaker pods by UA are a great option for you. They're constructed of solid hand laid fiberglass and will house most 6.5" speakers. These UnderGround speaker pods come standard with a black textured finish to match your OE Slingshot panels. Please note that depending on the brand of speaker you use for these pods that some trimming may be required.
More info about this product can be found here: UnderGround Auto Styling Inside Arm Rest Speaker Pods for the Polaris Slingshot