I agree with everything that ok4450 said, and I will add that my friend’s experience with having a remote start system installed on his new car was proof that you should have this job done at the dealership. Further, even if the dealership is suggesting an aftermarket company’s remote start system, make sure that the one you have installed is the genuine one from the car’s manufacturer.
Shortly after getting his car back from the installation process, my friend’s Rav-4 began exhibiting bizarre, random electrical problems. After 2 visits to the dealership failed to eliminate these problems, I composed a demand letter to Toyota, informing them of our intention to file a Lemon Law complaint if the 3rd repair attempt was unsuccessful.
Because NJ’s Lemon Law is so pro-consumer, the result of my demand letter was that Toyota sent both their Regional Maintenance Supervisor and a Japanese engineer to the dealership to repair this new car. Within about 3 hours, they fixed it, even though a solution had eluded the dealership’s own mechanics on two prior attempts. If they had not fixed it on this 3rd attempt, my friend would have demanded (and would have received) a full refund of his purchase price, including registration fees, so Toyota corporate was very motivated to repair it on this last possible repair attempt.
How does this relate to the OP?
Because if the installation had been done anywhere other than the dealership, then the Lemon Law would not apply, and–in fact–if my friend had succumbed to the dealer’s recommendation to allow them to install a “superior” aftermarket brand of remote starter, rather than the genuine Toyota article, the Lemon Law also would not have applied.
With a leased car, all of this could get even more complicated, simply because the lessee doesn’t actually own the car, and he could wind up paying more at the end of the lease because he caused damage to the leasing company’s car.
Leasing might make sense if the car is for business, and can therefore be deducted as a business expense. For somebody who will use the car only for his own purposes, leasing is a losing proposition, IMHO. And–IMHO-- whether buying or leasing, having any type of aftermarket equipment installed on a new car is like putting your own head in a noose.