Hi everyone,
Today my alarm went off unexpectedly for the first time since I got my LS400 Mark 4 and I immediately remembered that when my Mark 1 alarm kept going off, I had called out an alarm repair firm, who told me that a strip of indigestion tablet foil packaging in the centre compartment was interfering with the sensor's microwave pattern. He said that metal objects should not be kept in there for that reason. Today I had left my metal cased LG G5 phone in the arm rest storage area and that's why it went off.
I knew there were many reasons to buy the same model of car again, apart from the fact that I pined for another after I sold the Mark 1!