Subscribe to download
MR's On-board Diagnostics GUI

Vehicle makers will love seeing the actual operating values while trying their vehicle scripts!
It displays live values for prop_vehicle_jeep and prop_vehicle_airboat and Simfphys vehicles, with no kind of smoothing. It also works when sitting on a parented passenger seat.
Uh yeah, finally some good OBD software for Garry's Mod!

From top to bottom and left to right, you can see:

• The Workshop button
  
• The settings button
  
• The close button
  
• The RPM value with a background becoming red when over-revving
  
• An analog rev-meter with shifting markers
  
• The gear number
  
• The throttle amount
  
• The remaining boost duration
  
• The speed
  
• The suspension poseparameter values
  
• The steer angle

Clientside commands:

• gearbox_tester_mr_settings

Clientside variables:

• gearbox_tester_mr_auto
  
• gearbox_tester_mr_speed
  
• gearbox_tester_mr_position

• If "engine" → "autotransmission" is 0 then the gear stays 1. And as this dashboard is designed for vehicle makers, the RPM remains 0 as well according to the reported value (I do not calculate it with a formula of my own).
  
• The support for simfphys vehicles is limited because there is less available information through its API.
  
• The dashboard is a draggable OSD that you can move all around the screen, and it will stay in place!
  
• The title bar is hidden unless the mouse cursor is visible.
  
• The addon calls the hook GM:HUDShouldDraw( "gearbox_tester_mr" ) so you can programmatically hide the OSD.

• VCMod Handling Editor (in-game script values editor)
  
• Vehicle Scripts Information[wiki.facepunch.com] (by myself)