I have mixed feelngs on this topic,it is hard to find a happy med of sponsor and a real sponsor,example motor sponsors etc still have to pay they just get a break and maybe some help with gearing etc,i think chassis sponsor is the big defining line,if you have a chassis sponsor you should stay in a higher class as they are very hard to come by and you have to be a great driver to have one..
i have a mtr and tire sponsor but only race couple races a year(because of work) so i may be alittle faster than average but dnt stay as fined tund as a chassis spnsor driver does,yes i know that is my problem but..
i think jimmy does as good as he can specially no prizes to chassis sponsor drivers does help deture them from racing a lower class and racing better /faster driver does help you become faster!!