I have tried all methods to open trunk/engine lids. IMO, the easiest method is to retrieve the pull cable from the left rear light assembly by lifting the bottom with silicon spatula or equivalent. Shine flashlight and you should be able to see the wire cable. Use hook to retrieve cable and pull to release latch for engine lid. Connect jumper cable as shown in User manual and you should be able to activate release levers on the driver's side sill plate.
The other methods (removal of wheel well plastic/or jumping at the fuse box is cumbersome and inconvenient. I have used this technique on many 996s and have always been successful. FYI, I own a 1999 996 Red Guards cabriolet with 37,000 original miles. Will keep it for my son.
