S13 Floor Brace? Not sure what it is called but look!

[fender-startocaster]

Price $120

For S13

Not certain on brand. Could be knock off.

[s-cargo]

Looks like a knockoff do luck bar.. Do Luck - Silvia 180SX rear crossbar for - Nengun Performance (http://www.nengun.com/do-luck/silvia-180sx-rear-crossbar-for-258888)

Not sure how this would mount right on the floor with those supports being vertical tho..