I can't think of anything under / in the dash, that's going to cause a coolant leak other than the heater core.
If that was the problem you would notice it. Keep on them before the warrenty is up!!!
That looks nice but the peaked fenders are not the same as these bolts ons. The 6th Gen does have the fender peaks just not as pronounced.
No right or wrong just personal preferences..
Funny the first 5 Gens got by without them with no problems. If they hadn't been put on the 6th Gen I don't think anyone would be asking for them.
Use them if ya need them & ignore them if you don't no big deal either way.