A slew of mod questions for you: sound deadening, HIDs, speakers, and more!

Hello all!
So...I have a handful of questions, and I thought it best to not bog down the forum with half a dozen different threads about all of them.
Feel free to answer any or all...thanks in advance!!

1. I've been working on applying sound deadening material to my doors. I've been pleased with the results so far, but think I could stand to see more improvement. The issue I'm running into right now is the vapor barrier: it's my understanding that the whole point of sound deadening material is to put it directly on the sheet metal of the door to reduce vibrations. Obviously, with the vapor barrier in place and stretched over the door, the sound deadener can't be directly applied to most of the metal. So: remove the vapor barrier, put down the sound deadener and good to go? Or remove it, apply sound deadener, reapply vapor barrier? Not sure what the best way to tackle that is.

2. Quick question here. Been looking at getting HIDs for my low beams. I have read some threads here where many say that standard H11 HID bulbs will cause ground shadows and that the solution is to use "H11B" bulbs. At the same time...I've also seen some threads about the Xenon Depot kits and from what I've read people haven't had the ground shadow issue with their HID kits. However - the Xenon Depot kits for 3rd gen Prius come with the regular H11 bulb stock but you can also get a generic H11B kit elsewhere on the site (not specified for Prius). Would I still want the H11b kit here? Further, with the XenonDepot kits, have you guys bought the additional relay harness, or going without? Right now they're having a 20% off sale, so without the relay harness it'd only be like $85 (about 105 with). Otherwise I was just looking at Morimotos. Preference between the two? (okay, sorry, that wasn't so quick )

3. I have a Prius 2 ('13) without Nav/JBL or any of that. It does have the stock touchscreen HU though. I feel the stereo is a LITTLE bit quiet. I'm hoping sealing the doors up well (#1) will help this out, but if it doesn't....is there any benefit to upgrading the speakers WITHOUT changing the headunit or adding an amplifier?

4. So I've swapped all my interior lights, reverse lights, and parking lights to LEDs. I'm thinking about swapping my turn signals for LED as well. I know I need to swap the flasher relay for this. From what I can tell, it looks like the front turn signals take a bit more work to do than the rear signals. Would there be any problems if I put the new flasher relay in and swapped the tails to LED but left the stock bulbs in the front for a short period of time?

5. Kind of random one here. I've seen a couple of people who have installed LED lights in the hatch - they replace the plastic covers that allow access to the license plate bulbs - and seem to have some sort of harness that splices into the plug for the license plate bulbs. The only place I've been able to find these is on eBay for like $200 or on Rakuten for around $50. I like the idea of these but not for $50 and DEFINITELY not for $200 or whatever it is. Hahaha. Anyone familiar with these pieces and know where to find them for cheaper?

OK! I think that's all for now...

 

I guess I'll have to work on replacing that then. Haha. I went ahead and bought some speakers as I could afford them now (and figured I might as well do them while I'm doing the sound deadening and only have to pry the doors apart once!) but was definitely planning on getting a new headunit at some point in the future.

With that in mind: would you get a new HU first or an amp? Both at same time or what?

One more quick thing.

Give it to me straight. How tricky is it to replace the flasher relay? I've heard some people say it's no biggie, others say you've got to be an amateur contortionist to make it work. I'm closer to NFL lineman size so....I wanna do the swap, but I'm a little nervous about that part ha.