The MG ZS is the MG Badged sports version of the Rover 45 (which was launched in 1999). The 45 in turn is a facelifted version of the Rover 400 which was launched in hatchback form in 1995 and saloon form in 1996. The MG ZS was built by MG Rover Group from 2001 until 2005.

The MG ZS was created from the Rover 45 after BMW sold off the then Rover Group in April 2000. Development of the model was greatly accelerated by the fact that Rover had already created the 400 Series prototype using KV6 engines and sporting suspension setups.

The Rover 45 donor car did not have a reputation for being a driver's car, but in fact it was the most suitable car in the Rover range for transformation into an MG sports saloon, its Honda heritage providing double wishbone front suspension and fully independent multi-link rear suspension.

As a Rover, the 45 was optimised for comfort rather than handling – however, as an MG the opposite was the case. The ZS 180, offering 175 bhp (130 kW; 177 PS) from the 2.5 L V6 engine and acceleration to 60 mph in 7.3 seconds, received favourable reviews in the press, with particular praise for its steering, handling and suspension.

The MG ZS 180 was the flagship car of the ZS range. It was available as a five door hatch or a four door saloon. The 180 included a number of changes over the standard ZS, as well as incorporating all of the features of the ZS+ models, the ZS 180 was equipped with a lightweight all alloy 2.5-litre Rover KV6 Engine, with quad cams and twenty four valves.

The 180 features uprated front and rear brakes, with 282mm front discs (up from 262mm) and 260mm rear discs (up from 240mm) as well as ABS and EBD, lowered sports suspension with uprated springs and dampers, uprated bushes fitted to front upper and rear trailing arms, 17" sports alloy wheels with 205/45 r17 tyres.

Externally, the 180 can be identified with deep front bumper, with front bib spoiler and fog lamps and sculptured side sills. A large rear spoiler could be substituted for a standard size as a no cost option

The 180 was facelifted in 2004, along with the rest of the range, and gained a bodykit inspired by the MG Xpower SV.

The kit incorporated wheel arch extensions with front wing vents, bumper spats and side skirts. The large 'Extreme' rear spoiler became optional, with a subtle lip boot spoiler fitted as standard. Complementing the new body kit were the new 17" 'eleven spokes' alloy wheels. Both the wheels and body kit were available as cost options on the rest of the range.
Model Engine Power Torque 0-62mph Top Speed
ZS 105 (Ireland & Portugal only) 1.4 L K-Series 102 hp (76 kW) at 6000 rpm 138 N·m (91 ft·lbf) at 4500 rpm 10.1 Seconds 110 MPH
ZS 110 1.6 L K-Series 107 hp (80 kW) at 6000 rpm 138 N·m (101 ft·lbf) at 4500 rpm 9.8 Seconds 119 MPH
ZS 120 1.8 L K-Series 115 hp (86 kW) at 5500 rpm 160 N·m (118 ft·lbf) at 2750 rpm 9 Seconds 122 MPH
ZS 120 Auto 1.8 L K-Series 115 hp (86 kW) at 5500 rpm 160 N·m (118 ft·lbf) at 2750 rpm 9.9 Seconds 115 MPH
ZS 180 2.5 L KV6 175 bhp, 177 ps (130 kW) at 6500 rpm 240 N·m (177 ft·lbf) at 4000 rpm 7.3 Seconds 139 MPH
ZS TD 2.0 L L-Series 99 hp (74 kW) at 4200 rpm 240 N·m (177 ft·lbf) at 2000 rpm 10.3 Seconds 116 MPH
ZS TD 115 2.0 L L-Series 111 hp (83 kW) at 4200 rpm 260 N·m (191 ft·lbf) at 2000 rpm 9.5 Seconds 120 MPH