You can upgrade from manual mirrors to powered, but you'll have to run the wiring and install a switch. I've done it, first from manual to power adjust/heated, then to add turn signal mirrors. Mine are the smaller mirrors in each case, as I don't care for the "Dumbo" style trailer tow mirrors.
Running wires under the dash isn't for the faint of heart (or if you can't stand the sight of blood), because unless you wear those mesh fish filleting gloves, you're GONNA get cut up).
Any of the mirrors are direct bolt on, so if you go manual mirrors to manual trailer tow mirrors, it's a piece of cake to swap.
I have some photos of my install in my photo gallery. Click on the "heated mirror mod" link in my signature.
Running wires under the dash isn't for the faint of heart (or if you can't stand the sight of blood), because unless you wear those mesh fish filleting gloves, you're GONNA get cut up).

Any of the mirrors are direct bolt on, so if you go manual mirrors to manual trailer tow mirrors, it's a piece of cake to swap.
I have some photos of my install in my photo gallery. Click on the "heated mirror mod" link in my signature.