thanks for the reply.
actually pretty sure it isn't a meta issue as every add on car I spawn now seems to have a blue lighting below it and in the interior (which I can't seem to turn off) seems to be some kind of LED lightning effect but changing the led lighting settings don't change it - I think originally I got the effect by changing some thing within the menyoo trainer (saved that car) but now it seems to have applied itself to all addon cars since then that I spawn through Menyoo.....
Update:Had it again today - was playing Michael in SP and got the color effect (in the car interior and under the car) every time I either spawned an add on car for him or jumped in a random car! (really weird because LED light options will not disable it) - so the effected seems to be saved across all mods/vehicles