A lot of people are saying to get the car lowered.
My Calais has the stock FE2 suspension, and to be honest, its already too low for Sydney city driving.
I am scraping on average three times a week on speed bumps.
I now know which speed bumps to be careful with, but it is annoying having to slow right down, and to drive over them on severe angles to try and limit any damage being done to the car, like I have some fully hetic lowered commodore.
I had lowered (legal height) on my previous falcon, and to be honest, the stock fe2 on this Calais is just as bad as that thing was.
Try the stock suspension for a couple of weeks, if you feel that lowering the car will not cause you grief, then go ahead.
But dont rush out and change the springs before sussing things out.
Also, keep an eye out on ebay for bargains things like interior / door trims, etc.
Calais / SSV Trims come round once in a while, giving you features such as door lights, leather arm rests, courtesy lamps, etc etc..
Just be aware of what fits and what doesnt.
A basic tip someone told me years ago, any mods you do to your car should have a purpose, not just be there for show.
Some good examples.
Tints - Look good and cool the interior of the car in summer.
LED Interior lights - help with power consumption, do not require replacement, looks good.
Wheels - Improve handling (with the right choice of wheel size and tire profile), also looks good.
Some bad examples.
Cut springs - May look good standing still, but you will always regret the pathetic handling once they are cut.
Cheap Chrome Rims - I have seen MANY cheap Chinese chrome rims shatter when hit with a pothole, causing more damage than they are worth.
Neons - Unless you are using them to illuminate areas like the boot, or interior when the doors are open, they serve no purpose.