--Dog Bone is the lower rear mount that tends to flex alot and allow torque toss, once replaced the engine sits still, an insert kit also works well.
--CAI is cold air intake, and it works well on our cars as well, once moving. Any open element sitting near a hot engine bay is bad. My intercooler N2O kit I am making will also spray a little towards the filter as well for that reason.
--The DV vs BOV is simply a BOV releases into the atmosphere, A DV doesnt. Once you start blowing off boost, and not Diverting it, a CEL (Check Engine Light) may appear, and compromise power. BTW, an intake will make the DV loud like a BOV if thats what you want...so I recommend staying DV and not BOV, even if you just wanna hear it spit.
The GTI is Adam , its a 03 Golf 1.8T Gray in color. He is currently in Auburn ALA, and comes here (home) frequently. He is chipped, 3" DP, 3" CB. CAI, Pulleys, Clutch /PP/Lt flywheel and all the -$100 things like DV, N75 etc etc. Great guy.