You will need the build manual supplied with your kit (or for some hop-up options, the hop up panel on the side of the box).  Alternatively use the link on the menu page to access Tamiya's resources of manuals and exploded diagrams with part numbers.
 

Don't have the build manual? Follow our MANUALS link at the top of this page.  This will take you to Tamiya's site where you can download a parts page for your car.
 

If possible, work out what your car's number is - example, 58347 is the popular Lunch Box kit.
 

Identify by studying the manual, which part you require.  
 

Identify which parts also come with the part you require. Most parts are supplied either in a bag or on a sprue - this will be identified on the last few pages of the build manual. Typically, these are identified by letters - e.g. "A Parts" or "Gear Bag A"
 

Find the part listed on the back page (or inside back cover) of the manual.
 

If the item is a spare part, it will be listed with a description and a seven digit part number - sometimes, where a part is available individually (e.g. snap pins or a drive shaft) the seven digit number will be listed by the part itself.  Where parts are only available as a part bag (e.g. "C Parts" etc) the seven digit number will be shown clearly near the parts listing.  All hop up parts, and some common spares, have a five digit number.
 

Note the part number(s) you need and look them up on the site.
 

If you need parts for non-radio controlled Tamiya plastic kits, these are not listed online. Please follow the Unlisted Parts link at the top of the screen to send us an enquiry.