Aoa my brothers, i will guide you , how to solve this "insert map disc" solution for japanese car DVD Nav systems NDDN-W54,55,56,58...
this error occur every time you disconnect your battery terminals,
all you need is the :Software disc for these players..!!
these sound system shop guyz charge you 500/- atleast for it (BILAWAJA), m uploading this software online for specified player models jin k software muje milay hain, so that k mera koi bhai wo pareshani na dekhay jo mene dekhi hay...
acha now gettin towards procedure...
All you need is the LOADING.KWI file for your model, this file contains data needed for loading that dvd player, burn it on blank Cd-R or DVD-R and give specific name to that cd/dvd according to your model ,dont create any subfolder, just LOADING.KWI file on cd
For NDDN-w54,55,56
Download link for LOADING.KWI file:
html
https://www.dropbox.com/sh/iwif56f9r613ffy/zXMVIyT0yv
you must give that Cd title (86271-V416A8)
burn it nd have fun...
Now NDDN-w58:
Download Link for LOADING.KWI File:
html
https://www.dropbox.com/sh/f7byhthhoidq34s/mmePTrb7D4
Give that Cd title (86271-60V450)
burn it and have fun...
Now u will have this fully working map disk, har baar paisay laganay ki zaroorat nae hay humare mulk may wese he bilawaja jeck lagata hay her bnda doosre ko thagnay pe laga rehta hay...
it will Inshallah work , nd if you get other models software disc do share it here, so that all software disks will be available at one place for all..
SHARE this thread as much as u can..bht se log is pareshani se dochaar hain 
talib e duaa...:)