Carew scored two goals against Reading on 12 January and was unlucky not to be awarded Man of the Match which went to Martin Laursen. He scored his first hat-trick for seven years and his first ever for Aston Villa against Newcastle United on 9 February in a 4–1 win. Gareth Barry allowed him to do so by kindly relinquishing his usual penalty taking duties so Carew could score his third. On 12 April 2008, Carew scored for Aston Villa against Derby County at Pride Park in the Premier League, in the 26th minute and Villa went on to win the game 6–0. On 20 April 2008, Carew scored twice against Birmingham City in the Birmingham derby at Villa Park, which Villa went on to win 5–1. He continued his scoring run with a header the following week, in a crunch game at Everton's Goodison Park, which finished 2–2. It would be his 13th and final goal of the season, crowning him as Villa's top scorer for the 2007–08 season.
Carew scored his first goal of the 2008–09 campaign by scoring the first goal in Aston Villa's 2–2 draw over Odense in the Intertoto Cup. On 14 August 2008, Carew signed a 12-month extension to his contract, thus taking him through to 2011 with his current deal.
Carew scored the opening goal in Villa's 4–2 win over Manchester City at Villa Park. He then scored his second league goal against Stoke City as they went on to lose the match 3–2 when Mamady Sidibe scored a late winner. He quickly added his 3rd of the season in the 2–1 defeat of local rivals West Bromwich Albion; and with Gabriel Agbonlahor on the scoresheet again the pair began to form a formidable partnership. They both scored again and assisted each other's goals in a 4–0 victory in the Premier League at Wigan Athletic on 26 October 2008. Carew scored the winning goal in the UEFA Cup for Villa in a Group F match away to Slavia Prague on 6 November 2008, Villa midfielder Steve Sidwell struck the ball towards goal but it hit Carew and went in, therefore the goal was credited to Carew; it turned out to be the winning goal and continued Villa's 100% record in the competition's group stages and the 1–0 victory saw Villa go to the top of the group. Carew made the headlines in late October due to his personal behaviour. He was fined two weeks wages by Martin O'Neill for being in a pub near a Birmingham lap dancing club the night before Villa's UEFA cup group stage match with Ajax.
Carew's sister, Elisabeth Carew, is an R&B singer. She released her debut album, Destructive, in 2008. She is competing in Melodi Grand Prix 2014 with her song "Sole Survivor".