not sure if this is a new problem for you or you're just tired of only being able to unlock w/ the remote when you're right next to the car. If "new", there might be an issue w/ your key's circuit board. Try your spare key to see if your original one is just wearing out as they are known to over time. Only recourse here is to replace the key head ($$) and get it programmed to the car by a dealer ($$$).
If it's not a new issue, there is a TSB for the 986 relating to "insufficient remote range". Here are instructions on how to remedy the problem. I did this on my '99 an changed my key from being a "right next to" to actually being a "remote"

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Remote Key Hack Extender by Stefan
The issue is the freq of the remote vs the length of the antenna wire (function of the freq). The full TSB calls for trimming the white antenna wire from the black sheathing to the 130mm (country dependent) length. Others have been able to get the fix by just exposing 130mm outside the wiring harness wrap as outlined in the hack by Stefan on the wiki (link above). Try the quick fix first, if not successful, then trim it.