I have bought and used two different driveway alarms.

Above is the DRIVEWAY PATROL-INFRARED ALERT SYSTEM.   I fell it is not worth anything.   It goes off repeatably for no reason and then doesn't sound when a car pulls in view of the infrared beam.  It runs about $20.00.

I took it back and got a refund after  trying it for three days.


 

Above is a  RWA-300R REPORTER WIRELESS DRIVEWAY ALARM.  It also uses an infrared beam but this one is really good.  I have used mine for over a year and am very satisfied with it.  It runs about $70.00.      


The only thing negative is it’s a little difficult to change the 9 volt battery in the sending unit. The positive is this battery lasts about a year. I am still using this alarm, with good results.

Anyone with any (and I mean any) skill in wiring can make a VERY loud buzzer to plug into this unit from Radio Shack parts; a buzzer; a 9 volt battery; an on-off minature toggle switch and a little plastic box. With that you can hear the driveway alert all over the house.

I'm sure that there are some costing much more that may be better.     

If this has helped you, take a second and punch the YES button below and maybe we can help someone else.  Thanks.