Speed Champions: 10 new parts request

[Steffen]

did you check the unofficial parts
http://www.ldraw.org/cgi-bin/ptlist.cgi
already?

* 11291 is available: http://www.ldraw.org/cgi-bin/ptdetail.cg.../11291.dat
* 18972: not available yet afaik
* 18973: not available yet afaik
* 18974: not available yet afaik
* 18975 is available: http://www.ldraw.org/cgi-bin/ptdetail.cg.../18975.dat
* 18976: not available yet afaik
* 18977: not available yet afaik
* 18978: not available yet afaik