The best way to access the firewall is?..

 

What?

 

The rubber piece that let's wires from the engine room to the interior without allowing water to leak through

 

You acess the firewall grommet via the passenger wheel well. It's tucked behind the liner, under the battery tray. On the interior you can access the other side via the footwell. Other then jacking the car up to access it it's a piece of cake.

Some pics in my build thread here: https://themustangsource.com/f692/ne...ck-sub-476186/

Tim

 

Is there also one on the drivers side?

 

I didn't look. Battery is on the right side, so I used the closest grommet. Remove right front wheel, remove wheel liner, grommet is right there. Easy.

 

Okay fair enough

 

Yes , there is one on the driver's side ...