Temperature Warning Beeper?
 

Owned an 88 RX7 convertible once. Thinking about getting another one. Burned up the engine on my old one because the fan belt broke while driving and I didn't notice the temperature gauge was showing the engine was overheating. If I buy another RX7 does anyone here know if I can buy a buzzer or beeper that will alert me if the temperature is getting out of safe range?

Rather than add a beeper to the existing gauge I'd just add a gauge with an alarm. Not intimately familiar with the FC but I doubt the stock gauge was linear anyway. So the aftermarket one will be more accurate and useful.
Just one example...

http://www.speedhut.com/gauge/GR-WTR...FQ-QaQodXHEP4A

Did you know that the belt broke while you were driving?

I was driving on the freeway and the engine seized. I pulled over, opened the hood, and the fan belt, or one of the belts was missing; sitting someplace back on the freeway I presume. I do recall looking at the dash when it first happened and the temp needle was pegged to the right. I don't recall if the gauge had a red warning light or not.

That car ran so sweet until then. I put in a replacement engine and it ran fine but the exhaust was never the same as I think the first part of it was messed up from the engine freezing. Looking back I should have replaced the entire exhaust and put in some kind of temp warning device like I'm asking about now.

If the fan belt broke, the alternator wouldn't be spinning so all the warning lights should have been on.

As others have suggested there are aftermarket coolant temp gauges with alarms built in. In the form of a gauge face that changes colour or a buzzer.

First of all, is the water pump on the fan belt path? I don't recall any warning lights. Secondly, I did find this:

DIGITAL TEMPERATURE CONTROLLER GAUGE ALARM ENGINE WATCHDOG CAR OVERHEATING PROBE

Now I have to find the right car.