In my '99, there is an auxillary pull cable routed to the Radiator opening on the passenger side (Rt. side). This runs directly to the latch. A somewhat strong pull is need and the latch opens. Hope this helps...
The bonnet catch is down by the drivers door, one for the front and back which according to porsche locks itself if the car has no power. Porsche tell me to so something with the fuse box and something about a red wire which can pop the bonnet up but i aint doing that...
I will give the cig lighter a go I think halfords is still open if I be quick.