Grounding After Market Stereo/Head Unit

Hello. I'm not sure how the installer made that mistake, isn't that his job? Anyways, if you really can't find any metal behind the head unit somewhere, the next bet is to try and locate the ground cable inside the original wiring loom if possible. It's not the best way to do it but will have to do if you cant access any metal elsewhere. It should be a black cable. A multimeter or wiring diagram can be a great help if you need it. Hope this helps you.

Yes. it is his job. He didn't follow the manual when he installed the unit. Kenwood model's are somewhat different than other units in that the power amp/power antenna connection is on the blue wire with white stripe. He bypassed that. The kicker is, when I went back with a print out explicitly telling him to connect to the blue wire with white stripe, he ignored it. Long story, short, I got refunded my installation fee by the major electronics retailer after I connected the right wire. But I digress... Is there some sort of diagram of the Nissan Versa dash/chassis? Anyone know where the roll bar tubing is? How I can access it (without taking apart instrument panels, dash and glove compartment)? Or if I do need to take those things apart to access, anyone have instructions? Thanks in advance!