[ExoSanty]

first off, thanks!
i'm getting closer...

changed 'i' to "i" in settimerex: (dubble quotes)
ITimer[playerid] = SetTimerEx("UInfoBox", 250, 1, "i",playerid);

it still shows the health of a car to all players, with the health of the players own car overlapping it every 250 milliseconds. so the playerid to draw the infobox to is not correct yet:

i tried this:

if(playerid == ITimer[playerid])
{
TextDrawShowForPlayer(playerid, InfoBox);
}

no joy