spark plug
 

I am a new owner of RX8 2003 and I was advised to change my spark plug to cold start spark plug. Can somebody help me to find where can I buy this cold start as I am having difficulty starting the car. Thanks

You were advised incorrectly by someone who has no idea what they are talking about. Seriously. I promise you that "colder plugs" won't make any difference in starting than stock plugs.

What are your symptoms? The reason for hard starts can vary significantly, but the symptoms are usually pretty good at defining which reason is the problem, so the more detailed you can be about the condition of the weather, how long since you last drove, how many miles on your current plugs, wires, and coils, and how old your battery is...the better.