Is it possible to upgrade a 2009 Ford F150 with the Sync system and no screen to Ford Sync 3/4, or will I have to go aftermarket to get CarPlay?

On a 2013 Ford Explorer, if upgrading from Sync 2, will I lose any steering wheel or other controls when upgrading to Sync 3/4?

Is there another site besides 4Dtech to get the Sync 3/4 upgrades? Seems like I have seen another one before, but I can't think of it off the top of my head.

Foursynctech

I would go with Merge Screens Tesla-style Standard display and keep the analog a/c controls with knobs & buttons. It's expensive but I think it'd be your best option. the "Foursynctech" posted above doesn't seem to have an offering for your application.

Touch Screen Radio - Ford F150 Tesla Screen Upgrade

The other option is a standard double din from Alpine, Kenwood, etc. with a probably ill fitting Metra trim and a harness to keep your steering wheel controls, camera, etc. from Crutchfield.

Do you have a Merge screen? How long have you had it? Any issues so far?

They have the Sync 4 option whereas 4Dtech doesn't. Is there any reason, other than screen resolution to upgrade to the Sync 4 for $230?

Explorer is primarily the kids' car, so it doesn't really need to be the latest and greatest, but I plan on keeping it for a while if there is something that would make me wish I had Sync 4 five or more years from now.

I'd go with aftermarket at this point. Lots of choices out there that are cheaper and better than retrofitting at this point.