That’s quite a workflow you have there! I think DC is thinking of the HD formats. You can actually get HD video (AVC\Blu ray quality) on a DVD disc if the video is short enough. Of course the player has to support the format that you have chosen too. It’s a good cheap way of distributing HD videos on a disc to people that have blu ray players.
Anyway, a regular DVD resolution is 720×480. Even though mathematically, this is not 16:9 it is is resolution you need to use for output. A flag is added to the video that makes it display in a widescreen (16:9) format.
Are you adding menus so forth, or do you just want a DVD playable disk with the footage?
If you have enough space, have RaceRender make you a near lossless file (huffyUV is a good example) so you get minimum degradation of quality by the time your DVD video is rendered.