sorry for the double post, but i found the solution (for me at least).
with the lilliput 7" 629 touchscreen, the VGA/USB dongle that it comes with is the problem. The board has a trapezoid connector with 14 pins that latches on, and has a "screw-on" 9 pin connector on the other end, which connects the VGA/USB+RCA input cables to it. The "screw-on" 9 pin connector does not allow the inner wires to make contact, only 2 of the 9 pins would beep out with my friends multimeter. He cut the "screw-on" connector apart and physically connected all 9 pins and bam, it works. Here's a picture of the thing im talking about.
I really hope this helps everyone else who's having this problem. My friend is a genius with this kinda stuff, it didn't take him long to figure it out after we dismantled the whole thing....which I was hesitant to do after how long it took to initially install it.
Here are some random pics I took of the install. Of note, if anyone buys the pre-mounted Lilliput 7" 629 touchscreen with the double-din kit and wants to install it in a 2006 Lincoln LS, you MUST cut off the back of the double-din with a dremmel or something to make it fit.
Oh, and if anyone cares to know the specs on my build, here they are:
Mobo- ZOTAC GF8200-C-E AM2+/AM2 NVIDIA GeForce 8200 Mini ITX
CPU- AMD Sempron LE-1250 Sparta 2.2GHz 512KB L2 Cache Socket AM2 45W Single-Core Processor
RAM- 2x CORSAIR XMS2 1GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Desktop Memory
CPU Cooler- SILVERSTONE NT07-AM2 80mm CPU Cooler (Low Profile)
HDD- SUPER TALENT MasterDrive OX FTM32GL25H 2.5" 32GB SATA II MLC Internal Solid state disk (SSD)
Bluetooth Dongle- cirago BTA-3210 USB 2.0 Micro Bluetooth Dongle support Bluetooth 2.1
Case- Morex 5677 Mini-ITX Case w/ 2.5" HDD Mount with PSU
PSU- M3-ATX 125 Watt - Smart Automotive Power Supply
Monitor- Double Din Bolt in Kit with the 7" 629 Lilliput Touchscreen
GPS- BU-353 Weather-proof GPS Receiver
I think thats about it, anyway, heres the install pics :P. will post more later i guess. Hope this helps everyone.