With my T-5R it seems to work better if I shoot through the glass, i.e. try to not hold the remote so it's transmitting through the door metal. That remote works from about 15 feet but my wife's V70 remote has at least a 50 ft range and through glass/not through glass makes no diff.
Also I read here or elsewhere that one guy had better luck if he held the remote vertically with the back of it facing the car, the buttons towards him and the part with the key hook pointing up. Sounds like folk medicine but there it is. BTW the red light signals that the alarm is on. It should do one long flash when you lock the car, and then short flashe quite slowly.