two 'badge engineered' versions of the same car with separate numeric classification. The R20 received an all-new 2068 cc diesel engine in November 1979, Renault's first diesel automobile. Both the 20 and 30 were advanced in terms of safety, featuring front and rear crumple zones as well as side impact protection. Aside from the unusual proportions, the 20/30 also received unique, downwards-folding door handles on the first two model years. These were changed to regular units in August 1976, for the 1977 model year. In the market Reliability issues, such as niggling mechanical faults (which sometimes proved expensive to fix) plagued both cars throughout their lifetimes. This was a factor in the cars heavy depreciation on the used car market in the UK. Other large cars with steep depreciation included the Peugeot 604 and Rover SD1. Rust was another major concern (in a Belgian owner referendum 70% of owners named it as the car's biggest problem); as a response Renault improved rust protection and began offering a five-year warranty against rust on 1 January 1982. The Renault brand was never strong in the upper segments of the market, particularly outside of France. Coupled with the hatchback bodywork, anaemic engines (to suit the French tax structure), and quality concerns, export sales were always low. In the end, over 63 percent of the total 20/30 production was sold in the French home market. However, the Renault 20 and 30 was assembled from complete knock-down kit in certain countries. In Venezuela, the R30 TS was assembled between 1979 and 1984, while the R20 TS was assembled in Australia from 1979 to 1981 and in Thailand in 1979 and 1980. While never sold in the United States, the R30 was brought to Canada in small numbers (426 cars according to a Renault Canada employee). Changes Shortly after their introduction, it soon became quite clear that the Renault 20 was too underpowered to cope with the overall size and weight of the car and that the Renault 30 was seen as too expensive for what was effectively the same car. In response to this, the R20TS was introduced, and used a new four-cylinder 1995 cc overhead camshaft engine rated at (which was shared with the Citroën CX and later the Peugeot 505). The new 2.0-litre engine was universally regarded as a big improvement. The following year (October 1978) saw the introduction of the R30 TX,