For those of you having issues with freezing opponents: I found that wheeling it and crashing right at the beginning then initiating the cheat seemed to work quite well. No need to wait 20 seconds but idk, seemed to work.
However, using game version 1.0.0.1, freezing timer worked only with older version of trainer (1.00) and only in single races (which kind of defeats the point as one could only really make use of this cheat during time trials/perfect trajectory). Using the newer trainer, freezing timer cheat simply doesn't work. Never hear the "cheat activated". Tried changing administrator permissions on both, running in compatibility mode, placing trainer in install folder, etc. The other two cheats seem to work no matter what but freezing timer is being a little *****. Unfortunate too, as this is the only cheat I need cause of those damn impossible perfect trajectory missions ugh. Any help would be greatly appreciated!