The one I had used it's own built-in antenna, but as mentioned in the other thread you started, I would not buy one installed again, and instead opt for a good portable unit. To each there own though.
__________________
2017 Escape 5.0 TA
2015 Ford F150 Lariat 3.5L EcoBoost
2009 Escape 19 (previous)
“Most folks are about as happy as they make up their minds to be.” — Abraham Lincoln