From the listing of Senna’s First Point Scoring F1 Car for sale:

The last of the TG 183B series of cars was built specifically for Ayrton Senna and was debuted by him in his very first F1 race – The Grand Premio do Brazil in Rio De Janeiro. Subsequently he raced the car at Kyalami where he finished a creditable 6th and in doing so, scored his first world championship point. This was followed by a 7th at Zolder and in his final race in TG183B 05 was at the San Marino GP at Imola.

Interestingly this is the 2nd Senna Toleman to come up for sale recently. The other was the famous car from the 84 Monaco race where Senna was robbed of victory of a red flag. Information on that car can be found here with a cool £1,000,000 price tag.

From Wikipedia:

The Toleman TG183 was a Formula One racing car designed by Rory Byrne and built and raced by Toleman Motorsport. The car first raced in the last two races of the 1982 Formula One season driven by Derek Warwick. In the 1983 Formula One season an updated version of the car, designated TG183B, was introduced and Warwick was joined at Toleman by Bruno Giacomelli. The car also raced in the first four races of the 1984 Formula One season when Ayrton Senna made his debut in the Formula 1 championship alongside former FIM 350cc and Formula 750 motorcycle World Champion Johnny Cecotto from Venezuela.

The TG183 was distinctive in that it had twin rear wings and front wing mounted radiators. Unfortunately the front wing configuration caused the front of the car to move about at high speed and was eventually replaced by a more conventional front wing set up.

The TG183B was replaced after four races of 1984 by the Toleman TG184.