RT-eng is where you want to get it from. He sells on his website and on ebay:

http://www.ebay.com/itm/Solid-State-Mopa...=item258f9ac75f

Here is his website:
http://rt-eng.com/rte/index.php/RTE_limiter

You need the IVR3 model according to the second link I posted.
Under "Buy IVR3" just below the "View Cart" tab you can click on "Which Cars Use The IVR3". Your Polara is listed.