Overview Reviews Product Description MG-4-R-V-POS Installation Manual The 123MG-4-R-V-POS is designed especially for the MGA and MGB. This unit is especially designed for positive earth cars. Product Videos Custom Field Product Reviews Write a Review Write a Review × 123ignition Switched MG4 R-V Positive Ground Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *