Snippit

if(llGetAgentInfo(llGetOwner())&AGENT_ON_OBJECT){
            llSetTimerEvent(0.05);
            rotation my_rot = llGetRot();
            vector my_vel = llGetVel();
            rotation my_vel_rot = llRotBetween(<1,0,0>,my_vel);
            rotation skid = my_rot/my_vel_rot;
            vector euler_rot = llRot2Euler(skid)*RAD_TO_DEG;
            integer angle = llRound(euler_rot.z);
            if(llVecMag(my_vel)>5){
                if(angle>90)angle=90;
                else if(angle<-90)angle=-90;
                llSetLinkPrimitiveParamsFast(LINK_THIS,[PRIM_TEXTURE,0,"4a91bef9-fd43-43d2-e7d6-13d56753ab97",<1,1,1>,<0,0,0>,(float)angle/90]);
                llSetText((string)angle,<1,1,1>,1);
            }