Wish I'd taken GAP insurance!

Just a quick whinge....why didn't I take GAP insurance???? 

Someone has just smashed into my car (no fault of my own), written it off and I have been paid out £3000 less on my car than what I owe on the finance...I could take this on the chin if it was my fault.

Everyone I speak to said I have no chance of recovering this shortfall.

The system sucks!