[OXO cube]

making entrants put their name on the bottom of car chassis ( engraved . sharpie or sticker ) should remove any problem with duplicates 
whether it be team name . forum name . or RL name
  
1st US proxy i entered . i forgot this requirement and received a penalty 

tape or blue tack over screws is a standard requirement for most of the US proxies . so should definitely be employed here 

some also ask for body / pod screw tightening info on the bottom of the chassis 
bit OTT imo . but if tape or blue tack are employed . repositioning of screws should be discouraged during the series . and the cars should be ran as they arrive unless it is obvious the screws are fully unwound or missing  

no duplicate car numbers is a big thing over the pond also . 
dunno why . 
not a biggie unless you intend to run a manufactured tampo livery . stickie roundels temporarily fix this if entrants want to return their cars to stock 

also representing cars as how a 1-1 liveried car should look (even if it is a fantasy livery) in the class they are intended to compete in is heavily enforced . if it doesn't look the part it can be DQ'd

almost all of the above i have found myself in hot water for at one time or another
and never once an intentional breach
so easy to overlook the simple stuff when entering 

Kev