Normally I would say no to the Cucaracha horn but knowing it annoys or embarrasses your girlfriend so much , I would get one for sure . How much fun would it be to blow it when you pick her up at her house or in another public setting . I can visualize a parent having some fun dropping off or picking up their kid in front of their school .
I had a cockroach horn on my 1972 VW Super Beetle. afterall, it is called the a Bug! I also have a real train horn on my 63 Chevy 1 ton and an ah-oogah horn on my dads 51 Ford. As long as you don't use it so much it becomes annoying, its ok. The reaction of the train horns NEVER gets old..