Rather a long time ago there were areas of the car market not occupied by the OEMs. How about a nice bit of plastic for your car, sir?
This advert is from the 1992 Daily Mail Motor Review. The back pages of car magazines usually featured this kind of thing. After you bought your car you could get rubber mats, car seat covers (the loud, tweedy ones were best), sun roofs and moon roofs, engine additives and car covers. Fog lamps could also be added, the more the better.
Much of that market has disappeared. The back pages of the TG New Car Buyers Guide [sic] has ads inviting us to protect our wheels, car waxes and plug-in diesel upgrades. And an ad for a garage. So, nothing you would really notice had you bought them all. The meaning of this is that the design of the cars makes them almost unchangeable unless you really want to make a statement: badly designed bumpers and, perhaps, shade strips for the front window. It also means that OEMs want customers buying addenda from their catalogue, thus taking a bit of that market under their roof. I don´t think any of them offer rain shields, which says something about the improvements in water flow management and aerodynamics. The E20 wasn´t the most slippery vehicle and adding these transparent items probably made the cD even worse. Oddly, in 1992 the car would have stood out from the rest of the herd quite well without them. Having a BMW was more than enough of a statement. Such items constituted gilding the lilly.