[Android Head-Units] ervius:
well done, I've used rom dumper 0.82, and no recovery.img or boot.img, only I get system.tar, post here my build.prop, as you can see, my system build, is quit younger than yours.

# begin build properties
# autogenerated by buildinfo.sh
ro.build.id=KTU84Q
ro.build.display.id=RK1.ZRCY9250.V1.015.PJ30.LD-2015-10-30
ro.build.version.incremental=2015-08-25
ro.build.version.sdk=19
ro.build.version.codename=REL
ro.build.version.release=4.4.4
ro.build.date=Tue Aug 25 22:06:52 CST 2015
ro.build.date.utc=1440511612
ro.build.type=eng
ro.build.user=linxiaowen
ro.build.host=tony-desktop
ro.build.tags=test-keys
ro.product.model=rkpx2
ro.product.brand=rockchip
ro.product.name=rkpx2
ro.product.device=rkpx2
ro.product.board=rk30sdk
ro.product.cpu.abi=armeabi-v7a
ro.product.cpu.abi2=armeabi
ro.product.manufacturer=rockchip
ro.product.locale.language=en
ro.product.locale.region=US
ro.wifi.channels=
ro.board.platform=rkpx2
# ro.build.product is obsolete; use ro.product.device
ro.build.product=rkpx2
# Do not try to parse ro.build.description or .fingerprint
ro.build.description=rkpx2-eng 4.4.4 KTU84Q 2015-08-25 test-keys
ro.build.fingerprint=rockchip/rkpx2/rkpx2:4.4.4/KTU84Q/2015-08-25:eng/test-keys
ro.build.characteristics=tablet
# end build properties
#
# from device/rockchip/rkpx2/system.prop
#
#
# system.prop
#

#rild.libpath=/system/lib/libreference-ril.so
#rild.libargs=-d /dev/ttyUSB2
# Default ecclist
ro.ril.ecclist=112,911
ro.opengles.version = 131072
wifi.interface=wlan0
rild.libpath=/system/lib/libril-rk29-dataonly.so
rild.libargs=-d /dev/ttyACM0
persist.tegra.nvmmlite = 1
ro.audio.monitorOrientation=true

#NFC
debug.nfc.fw_download=false
debug.nfc.se=false

#add Rockchip properties here
ro.rksdk.version=RK30_ANDROID$(PLATFORM_VERSION)-SDK-v1.00.00 \
ro.rk.screenoff_time=60000
ro.rk.screenshot_enable=true
ro.rk.def_brightness=200
ro.rk.homepage_base=http://www.google.com/webhp?client={CID}&source=android-home
ro.rk.install_non_market_apps=false
sys.hwc.compose_policy=0
sys.wallpaper.rgb565=0
sf.power.control=2073600
sys.rkadb.root=0
ro.sf.fakerotation=false
ro.sf.hwrotation=0
ro.rk.MassStorage=false
ro.rk.systembar.voiceicon=false
ro.rk.systembar.tabletUI=false
wifi.interface=wlan0
ro.tether.denied=false
sys.resolution.changed=false
ro.default.size=100
#persist.sys.timezone=
persist.sys.timezone=Asia/Shanghai
persist.sys.language=en
persist.sys.country=US
ro.product.usbfactory=rockchip_usb
wifi.supplicant_scan_interval=15
ro.factory.tool=0
ro.kernel.android.checkjni=0
#set default lcd density to Rockchip tablet
ro.sf.lcd_density=160
ro.adb.secure =0
#add bu lupeng
ro.factory.hasGPS=true
hk.bt.name = rkpx2
hk.screenshot.location=/mnt/external_sd0

#project properties
hk.project.name=ZR-WR9250
hk.customer.name=ZaoRiCaiYang

#setting properties
hk.setting.factory.password=8888
hk.setting.logo.show=false
hk.setting.logo.default=0
hk.setting.volume.default=8
hk.setting.language.default=ENG
hk.setting.screenshot.location=internal
hk.setting.rds.enable=true

#system UI properties
hk.systemui.key.eject=false
hk.systemui.key.home=true
hk.systemui.key.return=true
hk.systemui.location=top

hk.setting.funcwitch=1

hk.setting.function.dvd=true
hk.setting.function.avin2=true
hk.setting.function.dvdplayer=true
hk.setting.function.lights=true
hk.setting.function.dtv=true
hk.setting.function.atv=false
hk.setting.function.usb_ipod=false

hk.setting.factory.original=0

hk.setting.dvd_version_info=0

#
# ADDITIONAL_BUILD_PROPERTIES
#
ro.com.android.dateformat=MM-dd-yyyy
ro.config.ringtone=Ring_Synth_04.ogg
ro.config.notification_sound=pixiedust.ogg
ro.carrier=unknown
ro.config.alarm_alert=Alarm_Classic.ogg
dalvik.vm.heapstartsize=8m
dalvik.vm.heapgrowthlimit=64m
dalvik.vm.heapsize=384m
dalvik.vm.heaptargetutilization=0.75
dalvik.vm.heapminfree=512k
dalvik.vm.heapmaxfree=8m
ro.setupwizard.mode=OPTIONAL
ro.com.google.gmsversion=4.4_r3
ro.sf.lcdc_composer=0
debug.hwui.render_dirty_regions=false
keyguard.no_require_sim=true
ro.com.android.dataroaming=true
ril.function.dataonly=1
persist.sys.strictmode.visual=false
dalvik.vm.jniopts=warnonly
ro.rk.bt_enable=false
ro.factory.hasUMS=true
persist.sys.usb.config=mass_storage,adb
ro.factory.hasGPS=false
ro.kernel.android.gps=ttyS0
ro.factory.storage_suppntfs=true
ro.factory.without_battery=true
ro.product.version=1.0.0
ro.rk.small_screen=true
ro.product.ota.host=www.rockchip.com:2300
persist.sys.dalvik.vm.lib=libdvm.so
ro.kernel.android.checkjni=1
dalvik.vm.dexopt-flags=m=y
net.bt.name=Android
dalvik.vm.stack-trace-file=/data/anr/traces.txt

I used beyond compare to compare all files inside /system in yours and mine, and really few, few few differences there are, maibe great differences are in MCU part of our car unit.

I continue to study on it, and pick up your recovery image, trying to unpack it....

see you later.

UPDATE:

32 Mb of recovery??? seems to be quite large!

ok, let's analyze it! ;)