I have a 06 260 DA. Was the factory...

[SMUZ]

I have a 06 260 DA.  Was the factory vhf radio installed behind/under the "dash"?  That's where mine is located but I'm thinking the previous owner put it there.  It's a ridiculous place to put it. 

[wingless]

Welcome to the forum.

An online examination shows many placements for the radio on that boat.

Here is one location.

https://images.boattrader.com/resize/1/9/0/7890900_20210519105800603_1_LARGE.jpg

If the radio placement is difficult at the helm, then placing the radio in the salon and using a Command Mic at the helm might be a good alternative.

https://www.icomamerica.com/en/products/marine/commandmic/commandmiciv/default.aspx

[Beachwinds]

Replaced my 07 290 radio and yes the factory installed main base of radio was behind the dash. Was a pain to remove and reinstalled a similar garmin radio