They should work well, but I'd connect them as they were in your previous HU.
The roof antenna is for FM and the rear window antenna is for AM.
Problem is i don't know which one was ih which connector
I will plug only one antenna to see what happens on the radio, then the other one.
Are you sure for that the antenna 1 is a roof antenna for fm, antenna 2 is a rear window JUST for am?
Because in that case, if my roof antenna is weak, i will need to put the oem antenna back on the car and stash it somewhere, since the shark antenna is my gps signal antenna.