Cfg83 pretty much covered it. I'll just add that lowering may change the way your suspension works. It'll not only be a harder ride (even harder with tires pumped to a higher pressure), but suspension elements will be spending more time at slightly different angles, which may cause more wear.
The new trend in airdams is that the center is cut out. This still pushes air away from the front wheels, but reduces frontal area by letting air under the car. This works well only if:
- Your wheels are cleaned up (flat hubcaps, closed gaps),
- You have a good bellypan.
Lower suspension and airdams can also cause problems with scraping. A bellypan protects the underside from mud and salt.
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e·co·mod·ding: the art of turning vehicles into what they should be
What matters is
where you're going, not
how fast.
"... we humans tend to screw up everything that's good enough as it is...or everything that we're attracted to, we love to go and defile it." - Chris Cornell
[Old] Piwoslaw's Peugeot 307sw modding thread