Window Tint - It's a must here in TX. I have Wincos film, which does a great job of blocking heat.
Downpipe - Why the APR pipe? It is quite expensive. There are other alternatives out there, but if you're going to add a cat-back at the same time then I would go ahead and just get one brand's full TBE. Pick the brand that has the best sound for you. I already commented on APR and Milltek in your other threadGo on YouTube and search for videos of the different exhausts you are looking at...you'll find more for the GTI but it should sound pretty much the same as on our cars.
Forge DV - Opinions on whether or not there is any advantage are a mixed bag, but yes, it should work just fine on the A3.
Dogbone Mounts - I haven't replaced my entire mount, but I did put on one of the inserts, and it really seems to help with wheel hop :thumb up:
Intake - Marginal, if any gains in power with an intake. You will get more noise. Carbonio less so than any of the varieties of "filters on a stick". There are some more complicated variations such as the BSH True Seal or Forge TwinTake that are supposed to have more gains than others. The biggest benefit to a filter on a stick intake is that you can remove the stock engine cover, which makes it easier to work on things like checking your HPFP cam follower, which you should doThe biggest benefit to running a Carbonio is that since it is pretty much the same thing as the stock intake, just with a bigger, carbon fiber fresh air scoop, you are less likely to get any flak about it from the dealer if you have to take the car in for any warranty issues. If you're out of warranty, I wouldn't bother.
Coilovers - There are a ton out there, it's just a matter of what you want as far as ride quality/characteristics, adjustment, and price.



Go on YouTube and search for videos of the different exhausts you are looking at...you'll find more for the GTI but it should sound pretty much the same as on our cars.
The biggest benefit to running a Carbonio is that since it is pretty much the same thing as the stock intake, just with a bigger, carbon fiber fresh air scoop, you are less likely to get any flak about it from the dealer if you have to take the car in for any warranty issues. If you're out of warranty, I wouldn't bother.