This is an actual picture of a TR3 Racer
a nice example of a racing TR4, of course racing with roadsters was formerly very popular, alrady shortly after invention of the automoble the first racing cars were all topless. But during the 60ties upwards most racing cars were raced as coupes or with a hardtop. Very poular those days was breathing the engine through 2 twin horizontal carburettors which pushed the power up quite noticeable.
left picture shows two Le Man TR racing cars, the left one a TR3 based TRS which already has elements of the future TR4 (tail fins) the right - what else - a TR4.. This picture, right, ist the TRS Le Mans