(www.geocities.co.jp/Playtown-Denei/5259/) and it turns out the files section features a couple of tools for CarEd, besides the flying Max addon, dating back to 2001..!
Firstly there's an ASC-to-OBJ converter, coming with a manual (in japanese ofcourse) (program is in english).
Back then, people were really reluctant to use PT2, and as CarEd can only import BRender DAT files, this little tool could have made it really easier for modders to import their models into CarEd for compiling (would have had to keep in mind how CarEd only supports planar mapping and one material per component though).
The second tool is a CarEd OBJ export plugin for japanese 3D modelling program Metasequoia, for a version from 2001 though I guess. I think it exports one component at the time? Still very nice once again, as back then there was only a BRender DAT plugin for 3ds Max R2.
Readme:
CarED形式OBJファイル出力プラグイン
メタセコイアのCarED形式OBJファイルを保存できるプラグインです。
カーマゲ車作成にはStudioMAXのプラグインしかないのでとりあえず作りました。
マルチフレームは対応してません。だからパーツ作成用です。
また、ポリゴンを増やしすぎるとCarEdでの編集が重くなります。
ヘルプのプラグインについてよりインストールしてください。
CarED format OBJ file output plug-in
This is a plug-in that can save the CarED format OBJ file from Metasequoia.
Since there is only a 3DStudioMAX plug-in to create Carmageddon cars, I made this for the time being.
Multi-object is not supported. That's why it's for making parts.
Also, if you increase the number of polygons too much, editing with CarEd will be heavy.
Please install to get more help about the plugin.
Both tools are kinda obsolete now ofcourse, but had we known about these 20 years ago, they could have made modding a bit easier