Found all hese in the default.xbe 

Put the codes in at the rider name screen (Case sensitive)

 To open   -   Code

Mr Poppy   - piggypiggy   
Mr Herdie  - foxieloxie  
Mr Perfect - perfection 
Bouncy     - RubberTime  
Al Gore    - Dracklier   
Respect    - BlingBling 
Mrs Meet   - PushBike   
TimesTable - Calculator 
FastToggle - EggNChips   
TimeToggle - Vindaloo    
Jayber     - who jhb 
Food Man   - who roger   
WildeWoman - who sara    
Model Man  - who woz 
Tommy2Trak - who tom 
Snow Man   - who richj   
Art Honcho - who matt    
Rodney     - who dave    
MouseMan   - who rob 
Cobber     - who glenn   
Bruce      - who lewis   
Movie Man  - who steve   
Boss Man   - who dom 
FillyOFish - who phil    
SickArtBoy - whokristof  
Scrabbler  - who jimb    
who max    - who tony
4CheesePls - who mumu    
The Bevil  - who del 
Will Will  - who will    
Night Owl  - who mark    
FanTango   - who mikey   
EgBxMonkey - who rich    
Cube Boy 2 - who james   
Anim Man   - who martin  
He Da Man  - who dan 
Cube Boy   - who bork    
TrafficMan - who pete    
Stinky Bob - who jimg    
Glansville - who stink   
Mr Glans   - who smell   
Yo Ho Ho   - .LANG   
Mr D.Bug   - .DBUG   
Mr D.Test  - .TEST   
Mr GP      - .PRIX   
Mr BestLap - .LAPT   
Mr Meet    - .MEET   
Mr Respect - .RESP   


Dont know whats going on with these ones but they seem to be covered by the ones above ;)

nejnej     - allall  
impimp     - haohao  
iffiff     - bowwow  
gowgow     - meepmeep    
oinkoink   - cowcow  
Mr Cheat   - borkbork
Mr Speiler -     