I purchased the lock pick and it was very easy to install. It does everything that the sellers say it does. I did notice that the gps doesn't work when its activated. so that's the main thing I dislike about it.

This thing is pretty awesome. Easy to install and easy to use. Makes the navigation actually functional as you can input info on the move. Also being able to scroll through the xm categories is pretty handy. I pod input is nice but would be cooler if you could control it from the touchscreen instead of handling the I pod itself. Video on the move is nice for long trips to! I highly recommend it.

Unit was easy to install. Small and compact so it easily fit behind the navigation unit. Worked as advertised and best of all it did not interfere with normal system operations.

I have a 2007 Yukon Denali and I have had nothing but problems with mine. I have had it installed since 3/2009. Coastaletech customer service is horrible!! Carlos, the tech support guy is great though. I ordered mine from a 3rd party and Crappy Coastaltech will not warranty it even though it is their product. The 3rd party said I could send it back and they could test it out? How in the hell are you gonna test it out?

My issues are Navigation is flaky, doesn't work consistently. Lately the navigation doesn't know where I am. Sometimes the Override option in the GMX switches from 3 to 2 and screws it all up. My latest issue is when I connect my iPhone 4s it will play the music but won't display anything on the screen. My other bug is now DVDs won't play on the front screen. I have just about had it with this product.

My firmware version is 1.4 but the site says 1.3. When you check the update link, it takes you to a dead page.

This will be my very last purchase from the USELESS company who only cares with selling and not supporting their product. I had an old GMX 320, and I upgraded to the GMX550. I had less problems with that although it had less functionality.

Sonic Electronix offered an RMA to send it back to Sonic and see if they can replicate the problem. I highly doubt they have a 2007 Denali sitting around to test my issues out on, so I passed on it. Now I am stuck with $320 worth of useless junk. I feel like I am using DOS when using my 550, so clunky and not smooth at all.

I am not frustrated as much with Sonic Electronix as I am with Coastaletech. They (Coastaletech) said since I didn't buy it directly from them, they don't honor the 1 year warranty. Coastaletech is absolute garbage. Stay away if you want a product that works 100% of the time, but if you want a product that works off and on feel free to waste your $$ on the GMX550. Hopefully SonicElectronix will stop carrying this product!!

I would recommend this to others who are wanting to add a camera input or wanting to bypass nav input while driving or bypass DVD input while driving. I would not recommend this to someone who is strictly looking to add iPod functionality to your system. The iPod functionality is sketchy at best when using steering wheel controls.
Pros: Price for options added, Ease of install
Cons: iPod functionality from steering controls works when it wants to, I can start my truck not touch the iPod and steering controls may work press play turn off truck start again steering controls will not work. Next time I start they may or may not work if it works from the beginning it will work 100% until the next time I try.

WOW, what a great device. Easy connections. Takes some time to get used to the controls, but well written in the manual.

The product worked as advertised. Great product. Very simple to install. One major draw back is the screen now flashes from "Greyed" out to normal. In order to execute one of the unlocked commands you have to push the button when the screen changes to normal. This alternating flashing occurs constantly while the system is in the unlock mode but returns to normal when the unlock mode is taken off. I have search around and no one seems to have a fix for it. I have even returned the Lock Pick for a new one and still have the same problem.

The GMX-550 does exactly what is advertised. My specific reason was the iPod interface and ability for a front camera. I installed the GMX-550 in my 2010 GMC Sierra and had to place it under the center console, forward of the utility tray and not under the radio as advertised. There is absolutely NO room for the wires and unit under the radio. It is very important to remember that when activate the NAV In-Motion option, your GPS does not work for a little over a minute. It appears that the vehicle speed is disabled or ‘zeroed’ in order for the NAV In-Motion to work while tricking the vehicle that it is stopped. I’ve had problems with the GPS catching up after exiting this function.

Adding a front camera allows very close parking and prevents bumper collisions. I installed a High Resolution 170 degree back-up camera from eBay ($18) under the grill.

Add a blue tooth interface to securely unlock doors, window, and other features associated with the vehicle control bus/protocols.

Pros: * VERY easy to connect matching wiring harnesses and plugs.
* Intuitive interface
* Reliable performance
* iPod, iPhone, iPad controls ported to the vehicle’s touch screen
* 6 feet of iPhone, iPad, iEtc, cable to reach front and back seats
Firmware upgrades
* Multiple video management configurations. Dual back
monitors, Front monitor, Video game input, Camera
Inputs

Con: * Lack of wiring diagram resources available to connect existing
(factory installed) rear camera functions.
* Intermittent problem not restoring GPS functions after NAV In-
Motion. On rare occasions you must manually return to
normal function.
* Factory “in-motion” warning from top of screen while in video
mode.

Bottom-line: I’m very happy with my purchase and the performance of the GMX-550. I am considering installing turn-signal cameras on the side mirrors to compensate for blind spots. I also used the back-up function and installed a mini camera above my trailer hitch and can very quickly land the hitch and ball at any angle with extreme accuracy. I look forward to additional firmware upgrades.

Has some kind of internal circuit breaker that trips out for no reason. It stop at the store and turn off the truck with everything working fine. Get back in and nothing works! black screen on the radio, no power, no sound. I've had to pull the battery cable to reset it.
But i still have it installed and don't want to be without my iPhone in the truck. It is still the best option out there, it just needs a few tweaks to make it better.