My car alarm went off when my next door neighbour set his car alarm, normal, Faulty? It's a 68 reg Honda Civic?

My car alarm went off when my next door neighbour set his car alarm, normal, Faulty? It's a 68 reg Honda Civic?

They didn't make a Civic in 1968!

It is probably a fluke. For a couple of decades security systems have used rolling codes (the codes change to the next one in the secret sequence each time it is used) and it appears yours and his had the same code, or at least in the sequence window, that time. If it happens again you will have to talk with Honda about it.

Of course it isn't normal.