You can have both. No need to delete the slider to get rear defrost.
Pre-2013 that was true. Right as the 2013s came out EVERYONE was confused, including the people at Ram that dealers call for advice on new products. At this point, though, the dealer you talked to is just a willfully ignorant doofus ;-)That's interesting because a dealer told me that adding the defrost on a '14 3500 Mega meant I had to drop the power slider. Useful intel, thanks.