the emblems on their boot lids: the WR had a vinyl 'quattro' decal or a brushed aluminium effect plastic emblem, the MB had chrome plated 'Audi', 'Audi rings' and 'quattro' emblems, whilst the RR had only chrome plated 'Audi rings'. The rear suspension was altered early on with geometry changes and removal of the rear anti-roll bar to reduce a tendency for lift-off oversteer. For the 1984 facelift, the wheel size went from 6x15-inch with 205/60-15 tyres to 8x15-inch wheels with 215/50-15 Pirelli Cinturato P5 tyres. At the same time the suspension was lowered by 20 mm with slightly stiffer springs for improved handling. For 1987, the Torsen centre differential was used for the first time, replacing the manual centre differential lock. The last original Audi Quattro was produced on 17 May 1991, more than two years after the first models of the new Audi Coupé (8B) range (based on the 1986 Audi 80) had been introduced. North American market Sales of the Quattro in North America began in the 1983 model year. They entered the all-wheel-drive market established by the AMC Eagle, the first full-time automatic all-wheel-drive line of passenger cars to reach mass production. The small Subaru Leone station wagon offered an optional part-time 4-wheel drive system in the US market starting in 1975. The North American Quattro was manufactured concurrently and were of the same design as their European 1982 model year counterparts (they did not include the minor cosmetic changes of the 1983 European model) and continued through 1986. Total sales in the U.S. totalled 664 units. The Canadian market cars were identical to the U.S. version with exception of the speedometer, which was metric. Official sales figures for Canada were 99 units, which included 61 sold in 1983, 17 sold in 1984, 18 sold in 1985, and 3 sold in 1986. The U.S./Canadian cars were equipped with larger impact bumpers with built-in shock absorbers, like the rest of the 4000/Coupé models. They did not have anti-lock braking system (ABS), but included air conditioning and leather upholstery. Most of the 1984 and 1985 Canadian models came without sunroofs. The remainder of the electric, suspension, and cosmetic updates took place at the same time as the European cars. The initial 2.1 L (2,144 cc, engine code "WX") engine for U.S./Canadian models included minor component and engine control unit (ECU) changes, lowered turbocharger boost pressure, different camshaft, as