Just some info, the kicker L7's like to be ported if this is going in a z I highly recommend you return them and get one or two rockford fosgate punch stage 3 12's instead of the kickers. Also mtx jackhammer amps "depends on model" can be poorly made look at a kicker amp if you decide to return. I am not busting on what you bought just some recommendations for your z. Also unless your plan to be heard from 2 blocks away 2 12's is not needed. You own a z that is already a lot of attention.
Anyway take a look at my z installs on my link. You will see where I have ran the power wire behind the battery through the rubber grommet there.
Depending on the amp and if it is a class d or a/b it my over heat under the seat. If it is a class d than no problems a class a/b may.
Here is the thread plenty of z installs to look over.
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