Had my Z4 about a year, 2007. Been perfect until this morning, all of a sudden, high pitched alarm from rear, wipers not working, electric windows not working, and central locking not working, car starting/driving perfectly, I replaced the battery today in case it was a battery problem, but still alarm sets off, not normal alarm, a constant tone high pitch, lasting about 30 seconds or so and then repeats, and whilst driving, I have no warning lights. I have had to disconnect the battery for it to stop. Any ideas, help or advice please?