Built as an iteration of the same platform used by all of its predecessors, the LR7 was the third Harrier prototype to use Chevrolet power.

[1] After failing to start on debut at Silverstone with experienced drivers John Bartlett and Robin Donovan,[2] the LR7 made sporadic starts in 1989 and struggled to compete with class leaders including the Spice SE89C and the Lola T594.

In 1990, after multiple DNFs and DNSs, the LR7 finally achieved a best result of third overall at Oulton Park.

[3] However, this result was achieved against a field of only six entrants in the series' dying days.

Less than one month later, the series ran its final race at Donnington Park and the LR7 was formally retired.