Are these overly expensive for the lotus? At my work we use a product called an EZ sensor on many cars. They are like $35 bucks and can be programmed to many different cars. Call a few quality local shops and see what they would charge to install and program them.
Should you be interested in purchasing new, please keep us in mind. All you need to do is visit My Lotus Garage and send in your VIN along with a brief description of the parts you are looking for. And we will be more then happy to help you out! Also we will no be undersold, should you find a part cheaper elsewhere we will meet and beat their delivered price.