The adapters you need for an aftermarket head unit are:
wiring harness adapter: Scosche VW01 - http://www.sounddomain.com/item/SCOVW01B
antenna adapter: Metra 40-EU10 - http://www.dfwsbr.com/crossfire/audi...%20details.jpg , i bought it at Best Buy; but dont tell the kid there you have a Crossfire; he tried to sell me the "chrysler antenner adapter"

that'll work great for the JVC. i bought the KD-LHX500. remember to use the RCA preouts, not the speaker level outputs. https://www.crossfireforum.org/forum...ead.php?t=5916