[Mauzen]

This is not your system, right?

Seriously, look at the script:

pawn Код:

Lock[vehicleid] = 0;

What do you think this line does?
Dont know? Look at the following line:

pawn Код:

SendClientMessage(playerid,COLOR_GREEN," Car open.");

Yes, exactly, it opens the doors of vehicleid.

So you want them to open on death or disconnect. Have you heard of callbacks? If not, search in the wiki wiki.sa-mp.com
Telling you even more what to do would be lame.