Hi Sailingdog and Darrinsailboattrash
Both the Sea-me and the Echomax are slightly different to the CARD in that they don’t indicate where the radar signal is coming from where as the CARD does.
However both the Sea-me and the Echomax will signal when a radar signal is in range. These can be both visual and an audible alarms.
They are really only any good offshore sailing as inshore waters they would be triggered off all of the time, however they both increase the radar signal return.
They can also be triggered by your own radar (just a note).
I only posted the information as the original poster asked if someone makes something similar, this is the closest I have found.
I also have no association with either company, but have the Sea-me and are very happy with it.