As for Toyota/Tom's run in the All-Japan Sports Prototype Championship (JSPC), here are their results over the years:
1983:
#9 Tom's 82C-Toyota - Round 1 (2nd)
#17/#19 Tom's 83C-Toyota - Round 2 (2nd), Round 3 (9th)
#81 Misaka Speed C-Toyota - Round 2 (DNF), Round 3 (8th)
1984:
#17/#38 Dome 84C-Toyota - Round 3 (DNF), Round 4 (7th)
#19/#36 Tom's 83C-Toyota - Round 1 (DNF), Round 4 (DNF)
#19 Tom's 84C-Toyota - Round 3 (DNF)
#35 Tom's 83C-Toyota - Round 4 (12th)
#36 Tom's 84C-Toyota - Round 4 (DNF)
#78 Misaka Speed 83C-Toyota - Round 4 (DNF)
1985:
#3/#45 Tom's 85C-Toyota - Round 2 (DNF), Round 3 (6th), Round 4 (6th), Round 5 (4th), Round 6 (4th)
#8/#57 Tom's 85C-Toyota - Round 2 (8th), Round 3 (4th), Round 4 (3rd), Round 5 (13th), Round 6 (DNF)
#35 Tom's 85C-Toyota - Round 5 (7th)
#36 Tom's 85C-Toyota - Round 1 (DNF), Round 2 (7th), Round 3 (2nd), Round 4 (2nd), Round 5 (3rd), Round 6 (DNF)
#37 Tom's 85C-Toyota - Round 2 (5th), Round 3 (3rd), Round 5 (10th), Round 6 (DNF)
#38 Dome 85C-Toyota - Round 1 (1st), Round 2 (6th), Round 3 (DNF), Round 4 (21st), Round 5 (9th), Round 6 (2nd)
1986:
#3 Tom's 85C-Toyota - Round 1 (DNF), Round 2 (2nd), Round 3 (DNF), Round 4 (7th), Round 6 (5th)
#5/#45 Tom's 85C-Toyota - Round 1 (7th), Round 2 (DNS), Round 3 (DNF), Round 4 (DNF), Round 5 (14th), Round 6 (DNF)
#12/#34 LM06C-Toyota - Round 4 (DNF), Round 5 (16th), Round 6 (10th)
#19 SARD MC86X-Toyota - Round 3 (7th), Round 4 (DNF), Round 5 (23rd)
#35 Tom's 85C-Toyota - Round 1 (20th), Round 2 (9th)
#35 Tom's 86C-Toyota - Round 3 (4th), Round 4 (2nd), Round 5 (24th), Round 6 (DNF)
#36 Tom's 85C-Toyota - Round 1 (4th)
#36 Tom's 86C-Toyota - Round 2 (DNF), Round 3 (DNF), Round 4 (DNF), Round 5 (9th), Round 6 (DNF)
#37 Tom's 85C-Toyota - Round 1 (3rd), Round 2 (8th), Round 5 (DNF)
#37 Tom's 86C-Toyota - Round 3 (DNF), Round 4 (4th), Round 6 (9th)
#38 Dome 84C-Toyota - Round 1 (DNF)
#38 Dome 86C-Toyota - Round 2 (4th), Round 3 (DNF), Round 4 (DNF), Round 5 (28th), Round 6 (6th)
#46 Tom's 85C-Toyota - Round 5 (DNF)
1987:
#3/#45 Tom's 86C-Toyota - Round 2 (DNF), Round 3 (5th), Round 4 (9th), Round 5 (DNF), Round 6 (11th)
#7/#77 LM07-Toyota - Round 1 (20th), Round 2 (7th), Round 3 (10th), Round 4 (7th), Round 5 (21st), Round 6 (DNF)
#36 Toyota 87C - Round 1 (3rd), Round 2 (1st), Round 3 (DNF), Round 4 (1st), Round 5 (DNF), Round 6 (DNF)
#37 Toyota 87C - Round 1 (DNS), Round 2 (DNS), Round 3 (DNS), Round 5 (DNS), Round 6 (DNF)
#38 Dome 87C-Toyota - Round 1 (16th), Round 2 (DNF), Round 3 (3rd), round 4 (DNF), Round 5 (DNF), Round 6 (DNS)
#50 SARD MC87S-Toyota - Round 1 (DNF), Round 2 (DNF), Round 3 (9th), Round 4 (17th), Round 5 (17th), Round 6 (7th)
1988:
#3 Tom's 86C-Toyota - Round 1 (DNF), Round 2 (DNF), Round 3 (14th)
#3/#45 Toyota 87C - Round 4 (DNF), Round 5 (13th), Round 6 (DNF)
#36 Toyota 88C - Round 1 (6th), Round 2 (DNF), Round 3 (6th)
#36 Toyota 88C-V - Round 4 (DNF), Round 5 (16th), Round 6 (22nd)
#37 Toyota 88C - Round 1 (7th), Round 2 (5th), Round 3 (10th), Round 4 (DNF), Round 5 (5th)
#37 Toyota 88C-V - Round 6 (21st)
#50 SARD MC88S-Toyota - Round 2 (10th), Round 3 (11th), Round 4 (6th), Round 5 (DNF), Round 6 (DNF)
1989:
#36 Toyota 89C-V - Round 1 (5th), Round 2 (8th), Round 3 (DNF), Round 4 (2nd), Round 5 (DNF)
#38 Toyota 89C-V - Round 3 (3rd), Round 4 (DNF), Round 5 (1st)
#50 Toyota 89C-V - Round 1 (DNF), Round 2 (10th), Round 3 (DNF), Round 4 (DNF), Round 5 (18th)
1990:
#36 Toyota 90C-V - Round 1 (1st), Round 2 (DNS), Round 3 (DNF), Round 4 (DQ), Round 5 (6th)
#36 Toyota 89C-V - Round 6 (DNF)
#37 Toyota 90C-V - Round 4 (3rd), Round 5 (8th), Round 6 (DNF)
#39 Toyota 89C-V - Round 1 (7th), Round 3 (7th), Round 4 (9th), Round 5 (5th), Round 6 (1st)
1991:
#36 Toyota 90C-V - Round 1 (3rd)
#36 Toyota 91C-V - Round 2 (3rd), Round 3 (1st), Round 4 (4th), Round 5 (10th), Round 6 (2nd), Round 7 (2nd)
#37 Toyota 90C-V - Round 1 (6th), Round 2 (5th)
#37 Toyota 91C-V - Round 3 (3rd), Round 4 (DNF), Round 5 (1st), Round 6 (DNF), Round 7 (5th)
#38 Toyota 90C-V - Round 1 (11th)
#38 Toyota 91C-V - Round 2 (8th), Round 3 (DNF), Round 4 (1st), Round 5 (7th), Round 6 (DNF), Round 7 (DNF)
1992:
#7 Toyota TS010 - Round 5 (1st), Round 6 (4th)
#36/#8 Toyota 92C-V - Round 1 (5th), Round 2 (5th), Round 3 (2nd), Round 4 (2nd), Round 5 (3rd), Round 6 (5th)
#36 Toyota TS010 - Round 6 (1st)
#39 Toyota 92C-V - Round 1 (4th), Round 2 (DNF), Round 3 (6th), Round 4 (3rd), Round 5 (4th), Round 6 (8th)
#99 Toyota 92C-V - Round 1 (3rd), Round 2 (DNF), Round 3 (4th), Round 4 (5th), Round 5 (DNS), Round 6 (7th)
The Toyota 88C was certainly not their greatest car, it was quickly phased out of the JSPC by the 88C-V and did admirably in the 1988 24 Hours, but other then that Toyota/Tom's has had much better cars.