so this guy gave me a mission to find some Feltrite Cyrstals, and I need 13 more. I checked the Shrouded place and found buggerall, so does anyone have any suggestions of more lucrative locations?

Depends what stage you are at if you spend enough time on disc one going in and out of the wasteland then you will encounter feltrite meteor showers which you chase down in ur vehicle. I will say tho that this mission does'nt count towards the obsessive compulsive achievement. And you only get an upgrade for the defib making it recharge slightly quicker.