hello everyone, im new here 😅 !
i have a 2003 Honda Accord & im wanting to install an AUX cord & I purchased an IS32 ISimple Tranzlt USB (universal product). It includes an audio cable, aux jack, USB port, radio input, & a power switch. Where should I ground my wires for power source?

 

I assume you've found an answer somewhere, but the factory ground location is good, as is any other screw into metal (not plastic).