Safety Upgrade HID (Xenon) Headlights & Light Emitting Diode (LED) headlamp bulbs:

As you are probably aware the headlamp units pop right out of the 993 using the release levers on each side in the trunk.

High-Intensity Discharge (HID) Low-Beam Headlamps:

You may not be aware that when doing a low beam HID conversion on the Carrera most any aftermarket HID lamp kit that includes the “slim” ballast will fit completely inside the headlight unit and is fully reversible. The generic kits are inexpensive but feature longer high voltage wires than needed for a 993 and so make of a less neat install than the kit offered by https://www.bergvillfx.com. 

Here are some useful notes if you plan to do this very satisfying DIY project: 

Appendix “I” “ Installing High-Intensity Discharge (HID) headlights on 993 the gotchas”. 

Light Emitting Diode (LED) headlamp bulbs:

Recently aftermarket LED headlamp bulbs have become available. For our cars using a xenon low-beam in combination with an LED High beam bulb has become popular. Keep in mind the LED high beams can be considerably brighter than the original Halogen bulbs and one's goal is not to blind the drivers of cars in the opposing traffic.