Rear lighting on the MGA changed significantly across production, the 1500, the Twin Cam, the 1600 Mk I and the 1600 Mk II each have different rear lamp configurations, with additional variations by export market. This section covers all rear lamp service items including complete lamp assemblies, lenses, bases, retaining rims, plinths, rubber pads, bulbs and mounting hardware.
Type 549 stop/tail lamp, 1500, Twin Cam, 1600 Mk I
The Lucas type 549 is the original rear stop/tail lamp with built-in reflector, fitted to the 1500, Twin Cam, and 1600 Mk I (not the 1600 Mk II). On 1500 cars and on Twin Cams to chassis 2192, the type 549 lamp also served as the rear flashing indicator, a single lamp performing three functions (stop, tail, flasher) through a single red lens. On later Twin Cams (chassis 2193 onwards) and on all 1600 Mk I cars, a separate rear flasher lamp (type 594) was fitted alongside the 549, so the 549 reverts to its primary stop/tail role only. MGOC stocks complete 549 lamp assemblies and the individual service parts: lenses, lamp bases, and the pads that sit between the lens and base and between the base and the car body.
The type 549 lamp shares its specification with the Austin-Healey Sprite Mk I "Frogeye", which is why several of the products carry "A+Frogeye" in their description, the same Lucas-pattern lamp with common service parts. For the rear plinth (the body-coloured mounting block between lamp and car body), the 1600 LHR plinth is stocked specifically for 1600 Mk I cars.
Type 594 'beehive' indicator lamp, later Twin Cam and 1600 Mk I
The Lucas type 594 is the dedicated rear flashing indicator lamp fitted alongside the type 549 on later Twin Cams (from chassis 2193) and on all 1600 Mk I cars. Its distinctive 'beehive' shape comes from the dome-profile lens, and it is often referred to as the beehive indicator. MGOC stocks the complete lamp assembly with amber glass lens and the individual service parts. Two lens colour variants are stocked: amber for home-market and most export cars, and red for cars supplied to the USA and Canada where the Federal regulations of the period specified combined red stop/indicator lighting rather than separate amber flashers.
Both amber and red glass lenses are stocked in the original type 594 specification.
Chrome lens retaining rim
The chrome-plated retaining rim that secures the lens to the lamp base is stocked as a Lucas L692-type retaining rim, a common item across front sidelamp, rear stop/tail lamp and rear flasher on MGAs of this era. The rim is a service item that tarnishes, pits or goes past polishing over years of road use; a replacement rim refreshes the lamp cosmetically without needing to replace the complete assembly.
Rubber pads
Two rubber pads are fitted to each rear lamp: one between the lens and the lamp base (sealing the lens against water ingress into the bulb housing), and one between the lamp base and the car body (sealing and isolating the lamp from vibration). Both pads are stocked as service items; perished pads allow water into the lamp, which corrodes the bulb holder and causes the common complaint of intermittent tail lights.
Bulbs and bulb holders
The twin-filament stop/tail bulb is a BAY15d double-contact bayonet type, 21/5W clear, 21W stop filament, 5W tail filament. Single-contact indicator bulbs are also stocked. A terminal kit is stocked for rebuilding bulb holders where the original soldered contact and fibre washer have failed; a common service item where corrosion at the bulb holder contact has caused poor connection over time.
1600 Mk II, type 647 rear lamps
The 1600 Mk II uses entirely different rear lamps, Lucas type 647 units on horizontal plinths on the rear panel, similar to those fitted to the Austin/Morris Mini Mark I. The 647 combines stop, tail, reflector and flashing indicator in a single two-bulb assembly and is handed (left and right are not the same item). The indicator lens section can be amber or red depending on market. Mk II rear lamp items should be ordered by left-hand and right-hand specification, and with the correct lens colour.
Mounting hardware
Lamp mounting uses No. 10 (32TPI) UNF pan-head screws with spring washers, common across the rear lamp, plinth and body-fixing points.
Ordering considerations
Rear lamp selection starts with the variant: 1500, Twin Cam (before or after chassis 2193), 1600 Mk I, or 1600 Mk II. For the 1500 and early Twin Cam, the type 549 alone covers stop/tail/indicator.
For later Twin Cam and 1600 Mk I, both type 549 (stop/tail) and type 594 (indicator) are fitted, the 594 lens colour depends on the original market.