Car Alarms: proximity rf, keyless entry systems, base question

Question
In reference to the different keyless entry systems that are available today that will allow you to unlock and lock your car when in a certain range, I would like to know what systems currently do this.  I am aware that they are somewhat unreliable, however I would like to research it further.  Any information you can give me would be great.  Thanks!

Answer
Well, that's a base question with alot of answers.
But the best way I can explain the range, or
lack there of, is the placement of the antenna.
If up high, in the window area, your range will
always be better if the keyless entry is under
the dash, and the antenna is not placed well.

You will also find the keyless range may depend
on if the system also has an alarm and remote
start, as the range on these combo systems are
quite good.

Have a look around at www.keylesscar.com for what
I sell here, and let me know if you have
any questions.

ALARMTEK