I have a nuvi 255 and cannot see how to secure in car mount
601756
As risskie has already stated you must have the plastic clip (or clasp) that easily snaps on the back of the GPS unit and has the socket that snaps onto the round end of the arm of the friction mount. The socket can be hard to snap onto the arm, especially the first few times you do it.
601757
If you are asking how to secure the actual garmin device itself, when you purchase the nuvi, it comes with it's own square, hard, black, plastic clasp that attaches to the nuvi. That then inserts into the pointed mount that sticks up out of the mounting plate. Then the sticky mounting plate sticks to the top of your dashboard. If you buy just the friction mount with the case, you cannot mount your nuvi without that aforementioned square hard black plastic clasp. You MUST have that clasp in order for it to mount onto the friction mount.
631738
It might be, it looks like you might be able to add a ram ball mounting plate to the back of the GPS mount (at least one bolt or screw). This is a great mount that I use for my Amateur Radio, it rarely comes off the windshield.
1335473
I don't use the provided mount. I have placed Velcro on the dash and unit - it is much more secure, has a lower profile from potential police and/or theft. Having it mounted this way it does not get into one's visual field and it works as it should.
933055
It will hold a 2555LM which is 5 3/8" by 3 1/4" with 1/2" to spare. So I'd guess your good, but you may want to measure your GPS unit. You should also have room for your charger and mounting clip in this case in addition to your GPS unit, if its depth doesn't exceed 9/16". I went with a larger case for my 2555LM and used this case for a Nuvi 1300. Just measure your unit and compare the dimensions with the ones above before you purchase. It is a nice case, I think you will be happy with it.
629759
I have only tried to mount it on the dashboard of my car. Everytime I use it and try to mount it on my dashboard, it won't stay there. In hindsight, I should have returned this but I threw away the box.
1907810
I'm not sure what you mean by dash mat, but I'd think a beanbag mount should still work. I've also found that placing the GPS just under the rearview mirror works well for me -- allows me to glance at the unit while checking the rearview mirror and doesn't block much area (but Cal and Minn don't allow it, and since I live in Cal I ended up with a beanbag mount). The vent mount (very inexpensive) has received some good reviews (I haven't used it), but it's priced at a point where you could try it to see if you like it (you won't be out much money, plus you can return it if it doesn't work). Of course you could go whole-hog and get a custom mount from ProClip or a couple of other gps mount manufacturers, but you're looking at 50 or 60 bucks or more).
1283601
If you search for GPS mount it will come up. It says amazon instead of Navgear. Looks exactly the same as this one.
195893
You can thread a strong metal cable under the car and through the two middle holes and secure it with a lock. If it's a snug fit at front and back it will be reasonably secure.
616142
You use the clip that comes with the GPS unit that is attached to the windshield mount. Just pops off.
21626
You can find the detail instruction video of this excellent AboveTEK car mount holder at: https://www.youtube.com/watch?v=a8lpqVpUqB0
2186905
You probably need screws; strong velcro would work too. I actually keep mine in the glove box.
1986727
There is a small black circle that you stick to your dash. At the end of the arm (mounting brace itself) there is a latch that you lock into place once the suction pad at the end of the arm (underside) is placed ontop of the black circle.
1274116
I am not familiar with your "already existing car mount" system, so I cannot answer your question. I can tell you that I absolutely LOVE this Garmin nuvi 3790T, however!
2066361
You may have faulty product. Mine is holding a Nexus 7 tablet in my off road vehicle over VERY rough roads without a problem. How do you have it mounted?
1850099
I don't know, sorry. It doesn't fit mine precisely but it holds it well enough and my Nuvi hasn't fallen out of the bracket ever.
713763
There is a USB cable that you can plug into that comes from the back of the unit. You can route the cable into your glovebox if you want it hidden or have it come out of some part of the dash.
1503117
I think all the Nuvi boxes are the same size, independent of model.It is great for the box and cable but does not hold the mount. You have to store that separately and it is awkward to store.