The "License Plate Rule" of Costa Rica

I thought you guys might be interested in this. I've been researching Costa Rica for a future holiday and I came across this thing called the "License Plate Rule" which stops certain cars entering Costa Rica on certain days of the week (determined by the last digit of your number plate).

you can check it out here: http://www.livecostarica.net/node/183

I hear they're enforcing this fairly heavily these days, so take note if you plan a future trip there.