I recently upgraded the rear door on my 2017 Lance 2185 with the RVLock V4.0 Keyless Entry System with integrated keypad and remote Fob to match the front door. Some of you may have purchased this option on your TT or TC but for those of you that didn't - BUY IT! It is really cool and having the ability to stroll around a campground without having to bring keys is great! We have small children who think it's funny to watch mom and dad panic when they lock us out of the trailer and the RVLock V4.0 prevents that from happening.
The install was very easy and I found plenty of how-to videos on YouTube.com. Total install time was about 10 minutes. The major downside is the price - $239.99. Ouch! But RVLock.com usually has holiday sales. I got mine for $192.00 with free shipping and an extra Fob. If you can spare $200, I recommend it. It's really cool, very convenient and any improvements to security is a plus.