I too have the SSDD Plate lights and love them.. makes a world of differen that £25-£30 lol. Often the less expensive mods seem to make the most difference.. take the spolier for £40 odd, the license lights etc..
Tyso.. depending on your budget dude, you can either got the HERTZ set up ESK 163L which is a plug and play almost and comes as a 3 way to replace your front door speakers, replace your underseat drivers and also adds tweeters.. that'll more than suffice your needs as by the sounds of it, you don't wanna go 'all' out.
Bear in mind though that if you DO go down the hertz ESK 163L route, you won't have much of a bass as the underseat drivers in the hertz range is also 6.5" (same as your OEM one). Yes they'll be better than OEM sound and yes you'll definitely notice a difference, don't expect much bass.
The other route is to find a 2 way component (i.e. Focal 100KRS) and separately buy underseat drivers such as SWS-Earthquakes (PM me if you want a linky) or JEHNERTS XE200. Both of these are 8", they'll fit quite easily in the same space as the OEM underseat drivers and deliver a more of a thumpy bass given the larger cone diameter and possibly more power compared to the hertz.
I know it's a lot to digest if you're new but we've all been there and asked a million and one questions (esp me) so keep questioning and work out what you want.
Ofcourse the latter set up (Focal 100KRS) and Earthquake shallow subs (which is what alot of people on here have - See B33M3R thread, including myself in my previous E90, it was a world apart from standard set up) will come with a slightly heftier price tag when compared to buying the Hertz ESK 163L but it also means you get a much better SQ.
Don't forget you'll either need to recode your HU to HIFI or get yourself a sound processor... of the ones, Helix (talk to Mob17), JL Cleansweep, Audison Bit One / Bit Ten and JBL MS8 seem to the most popular but again do add to your budget significantly... keep your eye on German ebay as they often have these listed.
You'll need wiring (alot on here get theirs shipped from across the pond, including myself on 2 occasions) from a guy called TECHNIC. He specifically designs these as Plug and Play so it means you do not cut/splice/tamper with any OEM wiring.. handy for when you come to sell the car .. and the wiring is obviously transferable on to your next BMW of course
Let me know if you need more on that. Alternatively it can be sourced from the UK and some one here will be able to help you on this but I have no experience in that and you'll have to start your own thread I guess to track down these people :-) To get it shipped from the US including shipping and all handling costs etc cost about £120-£130 all in and TECHNIC is even happy to mark down the price labelling on the customs form so you don't get stung by customs.
Apart from that dude, you'll need door speaker spacers which is about £20-£30 in total, underseat spacers IF you chose to get the Jehnerts/SWS or Kicker 8". If you get the HERTZ ESK 163L, you won't need underseat spacers as the speaker sizes of 6.5" remain the same..
Some sound deadening on door cards if you wish and you are ready to rock bud!
Long I know but worth knowing if you're planning to upgrade.. plenty of info on here dude shout for any help/pointers
