From the mazda rx8 features and specs page:

Start System? AKA remote start? This was my first lease and I missed my remote start dearly!

 

No, sorry, it's an RF keyfob, the door locks pop up as you approach, just have it in your pocket.

S

 

You can't start the car without being inside it and turning the little **** where the key would normally go. You also have to have the little transmitter remote on you. Just make sure you don't have a pacemaker or you might kill yourself.

 

What they do in cadillacs is take that piece that senses the key out, and stick a valet key in it full time, and hide it up in the dash. So that transmitter always sees a key. Then when you hit the button it just cranks as normal, when you get in you put the real key in, and go. Good deal.

 

How much does a remote start go for these days in a stick?

 

It comes with the Grand Touring Package, so it's $4510 for the package. It's not an option otherwise.