There is a TSB out for this and it's an aliminum foil part that sits behind the sensor that requires removal of the rear panal trim behind the seats and is at least party associated with rain hitting tha BACK window as well. it's often NOT associated with heavy rain but light rain instead
Just decreasing the sensitivity is not an appropriate fix if you want your alarm to function as intended. If you can't set it off in any other fashion when you're outside the car (like by fluttering a car cover or slapping windows and stuff) then you're alarm is NOT set too sensitively, so rain shouldn't set it off. The TSB that's out for the issue is the appropriate fix for the problem. Does it surprise anyone that most people don't seem to know about a known fix for the problem?
Also, considering you can't truly predict when it's going to rain, nor do i think it's appropriate for owners to have to "remember" to hit a funny key sequence when they "think" it's going to rain to turn off their alarm, i don't think it's asking too much to have them fix a known issue with the car even if it IS barely out of warrantte if it's been happening while it was under warranttee... and i found the problem while i thought it was under warranttee. I can put up with all kinds of wiggles and niggles in the car, but an alarm going off in the middle of the night is not acceptable when you park in very public densely populated areas.
Just to reiterate. You are not entitled to a full warranntee when you buy a new car according to Lotus policy, regardless of whether it's new or you're the first owner... Unless Ron Mann was just lying to me, the warranttee starts when the dealer has had it for 6 months (which lotus has record of), when it has more than 50 miles (which requires the dealer to punch in so you may be okay). If the car sat at port the whole time you may be okay. If they juggle the car between dealers every 5 months, maybe you okay.
I also imagine they can make exceptions and adjust the warrantty accordingly, so it DOES start when you buy, but that is NOT their policy, and it's pretty obviously not well advertised either.
I have not contacted a lawyer yet... i should have seen the writing on the wall when the sales manager made me sign an arbitration agreement.
I'm willing to contact the dealer and see if we can come to an agreement before bothering getting lawyers involved. I'm going to leave their name out of it right now until i see how they respond... but i have either Lotus or the Dealer on the hook for generating false documents so it could get interesting. I've got paperwork with the purchase that says the dealer received the car months after they actually took delivery.
The one other thing i haven't looked into yet is statute of limitations... I had a warranttee claim denied much earlier in my ownership for paint defects, and i have a funny feeling everyone involved figured out some of the "problems" in my paperwork (ie. I bought a used car, not a new car) that i only figured out recently and they must have used that as rationale for denial of fixing the paint problem becasue i never got a rationale for denial, not from my current dealer who didn't support me, not from the dealer i purchased it from, nor from lotus... it's all finally added up. I wouldn't be surprised if they said, hey, if we just deny it and keep quite on this it'll all be too late by the time he figures it out since he wasn't careful enough to go through his paperwork with a fine toothed comb, and he didn't think to get everything in writing.
I have to say, buying my g500 without a warranttee and knowing i'm on the hook to fix any problems has been a LOT more satisfying that realizing you've been circled jerked a few times.