Could it be possible that the R50/R53 MINI coupe, a car with twice the structual rigidity of the current BMW M3, could use some further structural reinforcment? As anyone who’s pushed the car hard on the track can tell you, it feels incredibly solid and stable in corners with no obvious need for an upgrade in this area.

However the aftermarket MINI tuning company M7 felt that an improvement could indeed be possible. So they designed a system of understruts that reinforce the chasis by spaning the width of the car upfront and near the center.

On the face of it this system would seem ideal for the MINI convertible. As with any car without a roof, the MINI convertible is decidedly less stiff than it’s coupe counterpart. However reviewing the Under Strut System on an open top MINI would just be too easy. So instead we put it to the test on the already stiff MINI coupe to see if there could be any real benefit.

Installation is fairly straightforward but easier accomplished with the help of a lift. Specifically it’s important to make sure you’re level during installation as you want to make sure the two required holes are drilled at the correct angles. Otherwise it’s simple process that doesn’t take too long with the included instructions.

Immediately after installation I took some time to drive around some of my favorites roads in Chicago however I didn’t have time to do any back to back testing. In fact the difference (based purely on memory from the car without the USS) seemed quite subtle. However that all changed once I got a chance to drive the car aggressively back to back with another MINI without the USS.

The difference was obvious entering and exiting several slightly cambered corners. Where the stock MINI felt good, the MINI with USS felt incredily composed and infinitely solid on the exit. It’s almost a hard thing to articulate but the car feels more planted and quicker to respond. The USS allow a driver who may have missed the turn-in point, to recover much easier. The car seemed to have quicker reflexes and in turn greater exit speed.

The stock MINI feels like a go-kart from the factory. With the USS, it becomes utterly point and shoot to a level that is entirely addictive.

The difference isn’t night and day mind you. It’s something that only rears its head in tight corners and aggressive driving (best done at the track). However if you are an aggressive driver than regularly participates in track days or autocrosses, the M7 Understrut System is a worthwhile upgrade that truly improves the feel and composure of the MINI.

MotoringFile Rating: 4.5 (out of five)

Where to Buy: The M7 Understrut System are available from M7 Tuning for $349 plus shipping.