I had a techauthority subscription, and I had a glance at the instructions on how to mount the OE plate holder. There is another tow hook hole on the other (driver) side. I didn’t catch which side it mounts. I should have printed to .pdf. Is there no threaded tow hook mount over there? I prefer it over there for better visibility to law enforcement. (Don’t want to make them grumpy for any reason).
I was also thinking of trying to find a huge bolt to just bolt the OE one to the tow hook mount, until lockem’s point about an emergency situation has me rethinking...
The OEM front license plate mounts above the left side grill. There is a removable plug in the fascia on that side, but it appears to be only cosmetic. There is no threaded hole in the bumper behind the fascia on that side and I strongly recommend against any modification to said bumper. As-of May 2016 this car had the best European crash test rating of any car (full size SUVs included, Volvo XC90 was dethroned) and that bumper is a critical component in achieving said result.
Anyway, there is nothing sturdy enough on the left side of the car above the grill to attach a license plate using only a bolt through said hole to. With Alfa's design you drill into the fascia and use some sheet metal screws to get enough strength and stability.
On the right side above the grill there is a threaded hole behind the fascia plug intended for attaching the OEM tow hook. Alfa9 and similar license plate mounts use this hole for their mount. The only issues I see with this approach are that the plate can rotate if pushed hard (brush type car wash), some extra time and tools are needed to install the tow hook, and I don't like the look. Of course that last item is my opinion and your opinion may be different. The big plus side to this approach is that the part is readily available and easily installed. Few Giulia owners want to use a brush type car wash, due to the damage to the finish on the car that these machines cause. One forum member had a custom bracket made that allows a quick swap between tow hook and license plate ; a pretty slick setup that resolves issue 2 but getting another one like it might be difficult.
The right side grill has sensors all over it. Many of these sensors are optional so if your car doesn't have them, go for it. I think only the most basic equipment Giulias will allow this though.
The left side grill has one sensor (parking?) towards the center in the vented area. It also has a vent towards the center and towards the outside. The center vent provides air to the radiator. For non-QV machines the outside vent provides air to the wheel reportedly to reduce aerodynamic drag. This outside vent is fairly large with sport equipped vehicles and I thought non-existent without sport but others have reported that there is still a vent there. A license plate mounted over the grill will partially block this outside vent. Anyway, partially blocking a vent for aerodynamics is likely no worse for aerodynamics that putting the plate directly in the primary air stream over the vehicle (Alfa9 and OEM mounts), although I do not know for certain.
The big down sides with the over-the-grill installation is that most plates will not fit, and no brackets are available. The former issue is often resolved by cutting down the plate and bending it slightly (the grill is not flat). At least one state issues plates that will fit. Apparently Australian plates will fit. The bracket issue so far has been resolved by using a mix of HW store fasteners. I think by making a bracket I can solve both of these issues, but I won't know until I have a car that I can measure.
jzchen: if your tires are at different temps left to right enough to cause tire noticeable tire pressure differences and you are not driving around an oval track you have a problem that you need your Alfa dealer to correct. Alignment and brakes would be the first things to verify. I do not think that the outside vents provide appreciable cooling to the tires, although I could be wrong...