RR, Rear right; RL , rear left; FR, Front right, FL front left. The lines, sometimes red on drag cars or aircraft are to show possible tire slippage on the rim.
Something very interesting going back further that the Chevron toy trucks, http://blog.hemmings.com/index.php/2013/03/15/the-hess-toy-truck-mess/?refer=news
Here's a look at what they did through the years http://hesstoytruck.com/1964-65-hess-tanker-trailer.html
In this months Hot Rod, really an incredible build. http://www.hotrod.com/featuredvehicles/hrdp_1305_thundertaker_1960_cadillac_superior_coachworks_hearse/
Read the whole post, most have web links usually in blue, http://www.hotrodhotline.com/speeddemon-breaks-world-land-speed-record you have to do your home work, don't tell me "the dog ate it"
Kenny Duttweiler 368 CID "Hellfire" engine.