Phone GPS should, honestly, be good enough. Your speed isn't fluctuating much at highway speed so you should have an accurate reading after a few seconds.
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35% Hooper Optik | Takeda Attack CAI | F.I. HFC | Hotchkis Sway Bar | Stillen 24row | OS Giken Super Lock LSD | TK Shift Knob | EVO-R Carbon Diffuser
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