Ehh, rreaaallly think about it. When I was 18 I thought I had all these great ideas for tattoos, most are out the window 3 years later on.
I'd much prefer to have an artist draw up an original art piece than band/show logos. Tattooing has moved ahead so much that you can really get a nice piece of art that you can appreciate all the time, even if your tastes in music/shows change. You should find a good artist who's style you like and go from there.
At 18 I loved RATM, RHCP, Primus etc etc, and had since I was about 10-13, I still like those bands but I wouldn't want anything directly linked to them tattooed in me.
It's really up to you, but take your time to think about it. A lot of people have transformers tattoos, but you might be fine with that (lately it's becoming even more popular for whatever reason), a lot of people have bass clefs (I have one on my wrist, I still like it because it's simple, but sooo many people have the same thing or always ask where the treble clef is to match).
As for 'whatever it takes', ehh. If you did do it, I definitely wouldn't do the star, that would just look childish and disproportionate IMO. But do you really just want to be ripping off other people?
Seriously, you have a lot of ideas going through your head, they'll change a lot over the years. For instance you might put the Z on your ribs or what not, then 5-10 years down the track want a nice piece (or bigger) and then just have to cover up. The ribs, though a hard place to tattoo, give you a lot of room and body lines to work with.
Oh and I agree with Latimour about the car, Merc should be a no no.