The rarest Plymouth Reliant ever seems to be the 1982 and 1983 Spring Specials, available April 1982 and April 1983.
It seems that only one ad was run in several nationwide publications, from 3-29-82 to 4-5-82 for the '82 Spring Special. I have not found any Plymouth brochure covering this model, would love a copy if one exists. The ad that ran was the same in all magazines, a multi car Plymouth ad that also showed the Horizon Miser, Turismo 2.2 and a regular Reliant SE Woodie Wagon. Some big city newspapers also ran a small promotional article with a black & white picture when it first came out, supplied by Chrysler. The '82 Spring Special had a trunk mounted luggage rack, 2 tone Light Blue over Pearl White ( only color choice), seperated by pinstripes, and the first level full wheel covers. The blue paint covered the hood and roof top from the rear of the small window forward. The A pillar, firewall, and other underhood metal was blue also. The door jambs were white. It looks like the Spring Special came in Custom form, as a coupe only. It had the small window louvers and the digital clock too, normally only available on the SE Coupe. My research shows that this option cost the customer $ 250.00 if they wanted it. All of the ads showed the SS Coupe with Blue Vinyl Buckets, but I do not know if it was only available with them, this special probably was.
The '83 Spring Special came out in the same time period in 1983. It lost the trunk luggage rack and 2-tone paint, but gained a white fake full convertible top. It was available again only in Pearl White. I have not found any advertisements for the '83 version.
Th '82 Dodge Aries had a version called the Spring Sport Special, with solid color paint, gold "zig-zag" pinstripe, and the trunk luggage rack and 2nd or 3rd level wheelcovers. Dodge had a 2 sided brochure for this model.
I have run across a '82 Reliant Spring Special and am discussing with the owner about purchasing it. They are claiming low miles, but the condition looks like it turned over. Still too expensive, but it is the only one I have seen since I seen a new one in a Plymouth showroom back in '82.