I had the Kenwood pnp unit. Mounted it with the adhesive mounting option on the dashboard and to the right of the driver (in a left hand drive car ). Wiped down the area first with an alcohol prep pad. Now, at first I panicked, because it changed the color of the area. Mounted it there, ran it through the cigarette lighter and used the FM modulator. It was very secure! However, I did have reception problems at times. So I removed it about three weeks later, carefully with a butter knife and wiped the area down with some interior protectant. Brought it back to the original color to the point that you can't tell it was even there.
Take home points.
1 - It's possible to use adhesive, however; I don't know what it would have done to the dash after several years. My experience was only for 3 weeks. (which did not cause any problems). I would try to find a better placement. A different unit than I had would probably mount in the cubby hole area. The kenwood couldn't because of the design of the bracket.
2. I would definately run it through an aux port. Many people have no trouble with the modulator, but I did. I would also get someone to run it to a hot wire and not use the cigarette plug. It works, but can be in the way sometimes.
3. I miss mine, I am either going to get a different model, or a reciever for the oem radio.