I suspect that you are the stage where you want to decide what you don't like about the car and then decide how to "fix"it.
Here are a couple of posts I made 10+ years ago on a BMW forum:
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Given all the "if I do this, will my warranty blow up in my face" and "why'd I get pulled over for my 20000k headlights and my .5% tintz" posts, I thought that I would give my take on modding.
Don't be a lemming. Just because others are doing a particular mod doesn't mean you do.
Decide what advantages a certain mod have for you. Be honest - is it sound, appearance or performance. Remember that very few mods will actually improve performance or real world handling.
Do your research. What disadvantages does this mod have? Will it affect your warranty? What can some of the unintended consequences be? Has BMW (or another manufacturer) specifically warned against this type of mod? What are the legal implications? Do the cops in your area enforce that particular law? Is it unsafe to you or others?
Is the full cost of the mod (parts, labor, increased operating costs) worth the benefit?
And finally
Are you mentally and monetarily prepared to pay for both the mod and the consequences of the mod? This includes paying for damage that the dealer refuses to fix under warranty because they believe it was caused by the mod.
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Absolutely correct. Everyone needs to decide if the costs plus the tradeoffs are worth it for you.
Take the BBK as an example. By the time it is installed it will have set you back anywhere between $3500 and $4k. It will give you zero (let me repeat that - zero) benefits in day to day driving and, depending on the pads, may sound like a squealing pig. The only benefit (aside from cool painted calipers and possibly slotted rotors) is on the track.
If you never - or only very seldom - track your car then you really need to think about that mod and do a cost/benefit analysis.
You might decide that the cool factor is worth it - perfectly fine - but don't try to convince yourself that you'll get any day to day braking benefits.
The same holds true for most other mods.
The point of this thread is to get you to think about your mods, the benefits, the disadvantages and finally - to be honest with yourself about why you want to do the mod.
Most reasons are fine - improved performance - improved appearance (obviously subjective but you shouldn't care what anyone else thinks) - or just bragging rights.
Some mods can't be justified - those that are dangerous (but might look cool - ask yourself if there is a non - dangerous mod that accomplishes the same thing) and those that negatively affect others.
Let's look at a few examples
Dark tint on windshields (and even side windows) may reduce your visibility to the point of being dangerous at night. There have been some guys here that say "the tint is fine, I just roll my window down at night and look out that" - where was that guy when they handed out brains?
If your objective is heat/UV rejection, then you can get the identical (if not better) rejection using a 60% ceramic tint. If you objective is "looking cool" then you might want to reconsider that limo tint for something you can see out of at night. Find a buddy that has that tint and drive his car at night. Ask yourself objectively "is it safe?"
Higher Kelvin bulbs. We know (objectively) that the HID bulb that gives you the best balance between visibility and low glare is about 4300k. I didn't make that up, there have been a zillion studies on this - both here and Europe - we can accept that as a fact for current bulb technology. Going significantly higher will reduce usable visibility and increase glare for oncoming cars so, while bluer bulbs may look cool, they may be dangerous. Is there an alternative?
Whiter angel eye (or angle eye if you're into geometry) bulbs might even out the appearance of the front of your car and may make the headlights look "better" but may have warranty and reliability pitfalls - something that needs to be researched before you do that as an alternative to high Kelvin headlamps.
Now that I've beat a dead horse, let me give you a cliff notes version:
Modding a car to personalize it can be a good thing
Consider all the consequences and implication of your mod
Be prepared to pay for anything your mod breaks
Do your research
Be honest with yourself about the reasons for doing a mod
A few final bits of advice - don't go into debt for a mod that brings no actual driving performance improvements such as wheels, radios, paint and trim etc. Wait until you have the cash in hand to do those.
Virtually no mod will ever be recouped at resale unless you return the car to stock and sell the mods. The only mods that might make your a bit more desireable are very conservative appearance mods - legal tint in places like Florida for example. You won't get more money for your car but it might sell quicker.
Don't cheap out on important things like tires, brakes and maintenance. Although everyone under 25 is invincible, those things could save your life.
Respect the laws that affect others (catless exhausts, high Kelvin bulbs etc.)