Wiersz MySQL na liczbę kolumn i sumę

Użyj zapytania przestawnego:

SELECT MIN(ID) AS ID,
       Car_num,
       MAX(CASE WHEN Service = 'shower' THEN Price ELSE 0 END) AS shower,
       MAX(CASE WHEN Service = 'TV'     THEN Price ELSE 0 END) AS TV
FROM yourTable
GROUP BY Car_num