Bit disappointed by the somewhat down on power CT4-V and CT5-V models Cadillac unveiled in May? Don't sweat it as the automaker is preparing proper fire-breathing successors to the 464-horsepower ATS-V and 640-hp CTS-V.

Prototypes for new CT4-V and CT5-V “plus” models were teased earlier this month at IndyCar's Chevrolet Detroit Grand Prix, and now we have spy shots of a prototype for the CT4-V plus taken while it was testing at General Motors' Milford Proving Grounds near Detroit.

Cadillac spokesman Michael Albano told Motor Authority at the reveal of the CT4-V and CT5-V that details on the more extreme plus models will be coming soon. Rumor has it that the cars will use the Blackwing designation that Cadillac has applied to its brand-exclusive 4.2-liter twin-turbocharged V-8.

Expect the CT4-V plus to be powered by a 3.0-liter twin-turbocharged V-6 with more than 400 hp while the CT5-V plus will likely use either the 4.2-liter twin-turbo V-8 with 500-plus hp or the same supercharged 6.2-liter V-8 that makes 640 horses in the outgoing CTS-V. A 10-speed automatic will likely be standard on both.

2020 Cadillac CT4-V and CT5-V

2020 Cadillac CT4-V and CT5-V

In comparison, the CT4-V features a 2.7-liter turbocharged inline-4 good for 320 hp and the CT5-V a 3.0-liter twin-turbo V-6 good for 355 hp. These models also came with a 10-speed automatic and the choice of rear- or all-wheel drive.

Judging by our latest spy shots and previous teasers, the plus versions will benefit from more aggressive aero and upgraded wheels, tires and brakes. No doubt the suspension will also be enhanced to reflect the track-focused nature of the cars.

Look for the CT4-V and CT5-V plus models to debut before the year is out. We should see them arrive as 2020 models.

The new 2-tier strategy for Cadillac's V-series is more than just a rebranding of the previous V-Sport and V models, as the automaker appears to be sharing the aggressive looks across both tiers, and likely some technology too. Cadillac will also sharpen pricing. Previously, buyers needed to shell out around $15,000 to upgrade from a standard CTS to the CTS V-Sport. However, upgrading from a CT5 to a CT5-V is expected to cost only about $6,000 to $7,000. There will likely still be a steep premium for the plus models, though.