No expert here but I'll give me 2 cents.
First I would ask some questions to get a better feel for the situation:
1) What exactly does this new key do when compared to regular keys? I don't know any car that needs multiple keys to open doors/trunks/turn the car on - should I assume we are doing some type of scenario where cars actually require several keys?
2) What is the current stage for this new product? Still on the idea stage?
3) In the case of moving forward will this product be able to be patented?
4) What dictates this as a good idea? Increase profits? Does the client has a specific target?
Regarding my structure I would focus on the following areas:
1) Customer's willingness to pay;
Will this new change actually increase the value of our product in the eyes of the customers and will it have any significant impact in the # of cars we sell or the price we are able to charge?
2) Cost Structure;
What will be the R&D investment to develop this new technology and how will this affect our ongoing cost in the future? right now the cost of a single key, when compared to the entire price of a car, is virtually nothing - will this new technology actually increase our variable costs moving forward?
3) The possibility of new markets.
In the case of developing this new technology and patent it, will we be able to use it in different markets? Maybe licensing it to other brands?
My overall hypothesis is that this doesn't look like a good idea because the product doesn't bring any real value to the customers and doesn't decrease our variable costs to justify the investment. To validate my hypothesis I will need to study the areas I previously mentioned.
This was just my rough ideas when quickly reading the case.
There are a few more areas I would go into more detail but for now feels sufficient.