The upcoming Yonge North Subway Extension is fostering a wave of change just north of Toronto, the promise of new rapid transit stations in the coming years setting off an avalanche of enormous development proposals that will bring yet another towering neighbourhood skyline to the region.

North of the current Line 1 terminus at Finch, the planned Steeles Station will be surrounded by a handful of large-scale, transit-oriented communities (TOCs).

The latest TOC in what is expected to become an ultra-dense community has been tabled to replace a car dealership complex at 7200 Yonge Street, one block north of Steeles Avenue and just beyond the 416's northern boundary.

It's a sprawling 7.36-hectare/18.2-acre site, currently home to a collection of car dealerships including North York FIAT/Chrysler, Roy Foss Chevrolet Buick GMC Thornhill, Infiniti/Nissan Willowdale, and Thornhill Hyundai.

The conglomerate of auto dealerships known as Auto Complex Ltd. appears to be led by the Roy Foss dealership based on documents submitted with the City of Vaughan in March.

Locally-based firm Graziani + Corazza Architects has been signed on to design the complex, the firm best known for its work on the famously-ugly Aura at College Park.

A staggering 18 buildings are proposed, ranging from blocks of three-storey townhomes all the way up to towers as high as 55 storeys, interspersed with privately-owned, publicly accessible spaces, a pedestrian-friendly woonerf and a new public park.

The tallest buildings would be concentrated on and near the site's Yonge Street frontage, with heights of 55, 50, 45, and 40 storeys on Yonge, and towers of 35, 30, and 25 storeys immediately to the west.

A proposed public road would divide the taller tower blocks from the medium-sized towers, mid-rises, and townhomes further to the west.

Buildings along this stretch include mid-rises and towers ranging from eight to 20 storeys abutting the rail corridor to the north, while blocks of three-storey townhomes would act as a buffer between the enormous complex and the suburban low-rise streets to the west and south.

The complex plans a jaw-dropping 307,669 square metres, or over 3.3 million square feet in residential space alone, with a total of 4,742 units spread throughout the dozen and a half buildings. This would be in addition to 8,119 square metres (87,393 square feet) of commercial space.

And yet, despite the approved subway station nearby and the project being touted as a TOC, the developers (remember that these are car dealerships in charge of the development) have asked for an astonishing 2,430 parking spaces, the majority planned for use by residents of the complex.

This means that around 50 per cent of the units in the complex would be allocated parking spaces, likely necessary to attract suburban-minded residents but almost entirely defeating the purpose of a community planned around, and justified by, rapid transit.

James Ricci, President of Roy Foss Automotive Group, tells blogTO that the project would be a "phased redevelopment over several years."

In the meanwhile, Ricci says "It's business as usual for all the dealerships on the property as the application process does not impact our day-to-day operations," adding that "the dealerships have deep roots in Thornhill and the surrounding areas: some of us have been serving customers here for over 60 years."