I just bought a CObra 29 wx nw st. I was wondering where I should mount this device inside the cab and where I should put the antenna on the outside. I was thinking either in between the visors above head but I run into having to still new holes which I really don't want to do. Any ideas?

 

Where you put your radio is all about personal preferance, I personally wouldn't mount it up high where the mic cord is gonna be dangling in my area of view and if on a rough road it'll swing everywhere in your face, get caught on stuff, etc.-kind of a pain. As for the antenna......a good magnetic base is a good investment, its a "bottom load" type and works very well. It is best placed in the center of the roof right over the passenger compartment. The antenna needs a good "ground plane" for it to work to its full potential and this location gives it a perfect one. After that you need to run a SWR test to make sure you get the full potential from your radio and adjust it accordingly. I have a Wilson "LIL WIL" antenna and run a Stryker 10 band radio with around 100-150 watts and it works ok for now, it would be perfect for your Cobra.
I used to own my own semi and played around trying to find out what worked and didn't so I do know the basics.
Hope some of this helps and is what you were looking for.

 

A lot of guys install them under the heater controls, just above the center console in the 98+

 

I've heard that but I believe a little but of trimming will have to be done. I don't want a whip antenna I would rather use a 4ft firestik. Can I mount on my front bumper?? It's made of steel.

 

If memory serves, I think the antenna should be away from electronics, ie ECU up front.

Check this

 

You could mount it on your bumper. The only drawback is the range will be cut by mounting it there. If your not worried about how far you can talk, like if your only gonna use it on trail runs where you would be close together, the bumper is fine. If you want to get more than 1/2 mile or so then not so good. With a low power radio like the stock cobra I don't think you would cause enough interference to worry about messing up the ecm. There are a lot of cb sales places on the internet that could answer that better than me tho....I've been wrong about stuff once or twice.....