First post here - and first time attempting to do anything to my new-to-me 2015 Fit EX. First car I've ever owned in fact, as of a couple months ago! So I'm very new to all this - apologies in advance.

I just got a new head unit (Sony XAV-AX5000) from Crutchfield. While installing it hasn't been quite as straightforward as I hoped, on balance it's probably been less complicated than I should have expected, given my inexperience. And with the patient help of my dad and Crutchfield support, I've been able to get it most of the way there.

In spite of that, I'm now wondering if it's time to throw in the towel and get professional help. Here are my remaining issues:

1. I couldn't find the reverse light wire that I'm supposed to connect one of the wires to. Without that, the reverse camera hookup won't work. (I also couldn't find the parking brake cable, which I'm also supposed to connect to… but I'm not sure I really need that? Apart from the reverse camera, I don't seem to be missing any functionality.) When I talked with Crutchfield support about this, they said I would have to reach through a panel on the side that seemed impossible to fit my hand through. I've inquired with some local car stereo installers I found on Yelp, and the estimates I've gotten back seem to hover around $125. I'm willing to spend that, but before I do, I just want to make sure I'm not missing some easier access method I could do myself.

2. Keyless ignition has almost completely stopped working. I would have assumed that it was related to something I did, except it was already increasingly unreliable over the last few months. That said, I replaced the battery in the fob just before I started this project, and didn't stop to verify that it had helped with the keyless ignition issue, before starting wit the stereo installation. With the new battery, it seems to be reliable at locking and unlocking the door, which wasn't the case before. But for keyless ignition, it now doesn't work unless I literally use the fob to push the button. Is it plausible that I did something to make the fob situation worse in the process of installing the new stereo? (The Crutchfield support guy didn't seem to think so.)

3. Lastly, I haven't gotten around to trying to install these replacement speakers I bought at the same time as the stereo. I assume that they will be a bit easier than the stereo - less splicing and soldering wires? It sounds like having someone install this for me would cost ~$150, fwiw.

Thanks!