Welcome to the forum!
Well then, where to start, lol
firstly, 9n is a great car, ive had 4 different models from 206, clio mk2, Vaux astra n the polo is by far the favourite.
sound wise, i went through the whole sound system upgrades first. cant really be noticed but sounds great. the stock speakers are good anyways.
mine came without speakers in the rear, the size is ur looking for is 6.5 inch and u could get some nice components to fit in the door panel but u
gotta be careful of the depth as its mounted into metal struts (mine was anyways).
you'll be looking at around £75 - 100 for decent standard component set up. in which u get 2 speakers, and 2 tweeter, wires and a channeler. Ie,
2 for high end (tweets) n 2 for mid tones. Ull also get a channeller which will make the overall sound better as it seperates the highs from the lows and sends
the frequency to the correct speaker. really easy to set up this system and halfruads can always do it at a ridiculous price if ur lazy.
then ull probly want to go for 6x9's or a sub and amp package. not both as they share the same boot space and air shared between them will ruin ur 6x9's.
u can find a decent amp package with sub for £200-300. fusion do bog standard amps but they are still good sounding and are relatively small for boot space.
completly ur choice. u can have 8" to 18" depending what sound u want.
Now ur gona need sometin to run that power on. im running components with an amp only on a pioneer DEH-50UB, £100 with rear aux through
either golves box or steering column aswell as USB. connects and runs really well with ipod, iphone, etc. u can only connect one amp to it though
so if ur looking for a monster kit then u'll need sometin more up market. but if ur just looking for a better sound quality, speakers and that head unit was muchhhhhh better for me.
External mods are also going at good prices for the 9n. if u want a pair of lowering sping then id personally go for either Eibach Pro kit for 30mm drop here (
http://www.potn.co.uk/p1333559.htm), H&N do a few good kits or there are Spax springs which i have also had in the past which served me well
http://www.europerformance.co.uk/pages/ ... ct=3807467. shop around tho, u could get a better price on ebay, etc. but ur looking to pay between £80 if lucky to new £130 for decent springs. u can consider coilovers but ur looking more into the £300-400 market as there adjustable to what u want, and u get more drop. stay clear of the any backstreet brand and stick to th spax or eibach for pure quality.
Body kits arnt greatly popular with the 9n tbh from waht ive seen and heard around. theres the votex kit that comes on ebay every so often and u can get the entire kit (front, back, skirts, split, etc) for around £300 on a good day but ull be looking to get every bit seperatly as its rare to see a whole kit sold together at a good price. i got quoted at £250 full body spray in a candy anthracite for a mk2 clio. but it really depends on garages, body kit, size, etc.
Alloys are a great addition, and make a huge difference. u can go after market and hit the bk, wolfrace, TSW, Enkiel, AEZ, Devil, Lenso, ZCW sort of scene or go for some VW standards. i know a popular choice is the BBS montreal
http://www.wheelcollision.com/wccpix/69774.JPG and there pretty standard to get hold of for around £150 - 200 on ebay new. when ur hunting around tho, make sure of ur size of the wheel. eg, mine is 5x100 stud pattern, and u want an ET between 35-45. i got some 17" BK 299's on atm, got em for £300 with a tyre package, which is a realllllllllllly good price for thos new. but the sky's the limit with alloys. spend £150 on ebay or go full out BBS for £500-1000 lol. they go up in price with size, material, etc. tyres your looking at anything from £100-200 for a set of 4 on ebay or head over to
http://www.mytyres.co.uk or a company called black circles for brand news. there great and cheap, plus u get a good fitting price at a local garage voucher.
In terms of insurance, this one is a right bugger. not sure of ur age but most companies have a policy of no mods under 25. examples of these are direct line, churchill, admiral, elephant for under 20, Tesco's car insurance, etc. just gocompare.co.uk and confused.com that up and everything u see as 'cant offer a quote' will give u an inkling of who does n who doesnt. if uve got a fair bit of cash i suggest getting in contact with either Adrian flux, Bentacre or HIC. they do modded insurance and cover everything for no extra cost, but i think ull find the premiums slightly higher. if its cosmetic, u will be fine, but if its performance enhancing, eg air filters, exhaust systems, then they'll grill u for everything u got. depending on ur engine tbh mate, give them a call tho as its seems to work out cheaper. adding named drivers such as mum n dad will nock it down aswel and you usually dont have to declare anyting inside the car. id suggest declaring tho mate, as if your invovled in a smash to a wall the insurance company will find an undeclared body kit or air filter and give u the finger aswell as a police call. plus if u hit someone else, they wont fork out so u pay everything, there car, ur car. so before u go carrering into a Ford GT, declare everything
u got exterior.
hope this helps,
chris